The signs and symptoms of diastematomyelia may appear at any time of life, although the diagnosis is usually made in childhood. Cutaneous lesions (or stigmata), such as a hairy patch, dimple, Hemangioma, subcutaneous mass, Lipoma or Teratoma override the affected area of the spine is found in more than half of cases. Neurological symptoms are nonspecific, indistinguishable from other causes of cord tethering. The symptoms are caused by tissue attachments that limit the movement of the spinal cord within the spinal column. These attachments cause an abnormal stretching of the spinal cord.

The course of the disorder is progressive. In children, symptoms may include the "stigmata" mentioned above and/or foot and spinal deformities; weakness in the legs; low back pain; scoliosis; and incontinence. In adulthood, the signs and symptoms often include progressive sensory and motor problems and loss of bowel and bladder control. This delayed presentation of symptoms is related to the degree of strain placed on the spinal cord over time.

Tethered spinal cord syndrome appears to be the result of improper growth of the neural tube during fetal development, and is closely linked to spina bifida.

Tethering may also develop after spinal cord injury and scar tissue can block the flow of fluids around the spinal cord. Fluid pressure may cause cysts to form in the spinal cord, a condition called syringomyelia. This can lead to additional loss of movement, feeling or the onset of pain or autonomic symptoms.

Cervical diastematomyelia can become symptomatic as a result of acute trauma, and can cause major neurological deficits, like hemiparesis, to result from otherwise mild trauma.

The following definitions may help to understand some of the related entities:

- Diastematomyelia (di·a·stem·a·to·my·elia) is a congenital anomaly, often associated with spina bifida, in which the spinal cord is split into halves by a bony spicule or fibrous band, each half being surrounded by a dural sac.

- Myeloschisis (my·elos·chi·sis) is a developmental anomaly characterized by a cleft spinal cord, owing to failure of the neural plate to form a complete neural tube or to rupture of the neural tube after closure.

- Diplomyelia (diplo.my.elia) is a true duplication of spinal cord in which these are two dural sacs with two pairs of anterior and posterior nerve roots.

Cleidocranial dysostosis is a general skeletal condition so named from the collarbone (cleido-) and cranium deformities which people with it often have.

People with the condition usually present with a painless swelling in the area of the clavicles at 2–3 years of age. Common features are:

- Clavicles (collarbones) can be partly missing leaving only the medial part of the bone. In 10% cases, they are completely missing. If the collarbones are completely missing or reduced to small vestiges, this allows hypermobility of the shoulders including ability to touch the shoulders together in front of the chest. The defect is bilateral 80% of the time. Partial collarbones may cause nerve damage symptoms and therefore have to be removed by surgery.

- The mandible is prognathic due to hypoplasia of maxilla (micrognathism) and other facial bones.

- A soft spot or larger soft area in the top of the head where the fontanelle failed to close, or the fontanelle closes late.

- Bones and joints are underdeveloped. People are shorter and their frames are smaller than their siblings who do not have the condition.

- The permanent teeth include supernumerary teeth. Unless these supernumeraries are removed they will crowd the adult teeth in what already may be an underdeveloped jaw. If so, the supernumeraries will probably need to be removed to make space for the adult teeth. Up to 13 supernumarary teeth have been observed. Teeth may also be displaced. Cementum formation may be deficient.

- Failure of eruption of permanent teeth.

- Bossing (bulging) of the forehead.

- Open skull sutures, large fontanelles.

- Hypertelorism.

- Delayed ossification of bones forming symphysis pubis, producing a widened symphysis.

- Coxa vara can occur, limiting abduction and causing Trendelenburg gait.

- Short middle fifth phalanges, sometimes causing short and wide fingers.

- Vertebral abnormalities.

- On rare occasions, brachial plexus irritation can occur.

- Scoliosis, spina bifida and syringomyelia have also been described.

Other features are: parietal bossing, basilar invagination (atlantoaxial impaction), persistent metopic suture, abnormal ear structures with hearing loss, supernumerary ribs, hemivertebrae with spondylosis, small and high scapulae, hypoplasia of illiac bones, absence of the pubic bone, short / absent fibular bones, short / absent radial bones, hypoplastic terminal phalanges.

In contrast to STD, the subtype spondylocostal dysostosis, or SCD features intrinsic rib anomalies, in addition to vertebral anomalies. Intrinsic rib anomalies include defects such as birfurcation, broadening and fusion that are not directly related to the vertebral anomalies (such as in STD, where extensive posterior rib fusion occurs due to segmentation defects and extreme shortening of the thoracic vertebral column). In both subtypes, the pulmonary restriction may result in pulmonary hypertension, and have other potential cardiac implications.

Babies born with Jarcho-Levin may be very healthy and grow up to lead normal lives. However, many individuals with Jarcho-Levin suffer from problems of respiratory insufficiency secondary to volume-restricted thoraces. These individuals will often develop pulmonary complications and die in infancy or early childhood. The disparity in outcomes of those with the syndrome is related to the fact that Jarcho-Levin actually encompasses two or more distinct syndromes, each with its own range of prognoses. The syndromes currently recognized as subtypes of Jarcho-Levin are termed spondylothoracic dysplasia and spondylocostal dysostosis. The disease is related to the SRRT gene.

Diastematomyelia (occasionally diastomyelia) is a congenital disorder in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra.

Diastematomyelia is a rare congenital anomaly that results in the "splitting" of the spinal cord in a longitudinal (sagittal) direction. Females are affected much more commonly than males. This condition occurs in the presence of an osseous (bone), cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords. When the split does not reunite distally to the spur, the condition is referred to as a diplomyelia, or true duplication of the spinal cord.

The clinical presentation of HFM is quite variable. The severity may depend on the extent of the area with an insufficient blood supply "in utero", and the gestational age of the fetus at which this occurs. In some people, the only physical manifestation may be a small and underdeveloped external ear. In more severe cases, multiple parts of the face may be affected. Some people with HFM may have sensorineural hearing loss and decreased visual acuity or even blindness.

Goldenhar syndrome can be thought of as a particularly severe form of HFM, in which extracranial anomalies are present to some extent. Some of the internal organs (especially the heart, kidneys, and lungs) may be underdeveloped, or in some cases even absent altogether. The affected organs are typically on the same side as the affected facial features, but bilateral involvement occurs in approximately 10% of cases. Deformities of the vertebral column such as scoliosis may also be observed in Goldenhar syndrome.

While there is no universally accepted grading scale, the OMENS scale (standing for Orbital, Mandible, Ear, Nerves and Soft tissue) was developed to help describe the heterogeneous phenotype that makes up this sequence or syndrome.

Intellectual disability is not typically seen in people with HFM.

It involves numerous anomalies including:

- Post-axial polydactyly

- Congenital heart defects (most commonly an atrial septal defect producing a common atrium, occurring in 60% of affected individuals)

- Teeth present at birth (natal teeth)

- Fingernail dysplasia

- Short-limbed dwarfism, mesomelic pattern

- Short ribs

- Cleft palate

- Malformation of the wrist bones (fusion of the hamate and capitate bones).

Robinow noted the resemblance of affected patients' faces to that of a fetus, using the term "fetal facies" to describe the appearance of a small face and widely spaced eyes. Clinical features also may include a short, upturned nose, a prominent forehead, and a flat nasal bridge. The upper lip may be "tented", exposing dental crowding, "tongue tie", or gum hypertrophy.

Though the eyes do not protrude, abnormalities in the lower eyelid may give that impression. Surgery may be necessary if the eyes cannot close fully. In addition, the ears may be set low on the head or have a deformed pinna.

Patients suffer from dwarfism, short lower arms, small feet, and small hands. Fingers and toes may also be abnormally short and laterally or medially bent. The thumb may be displaced and some patients, notably in Turkey, experience ectrodactyly. All patients often suffer from vertebral segmentation abnormalities. Those with the dominant variant have, at most, a single butterfly vertebra. Those with the recessive form, however, may suffer from hemivertebrae, vertebral fusion, and rib anomalies. Some cases resemble Jarcho-Levin syndrome or spondylocostal dysostosis.

Genital defects characteristically seen in males include a micropenis with a normally developed scrotum and testes. Sometimes, testicles may be undescended, or the patient may suffer from hypospadias. Female genital defects may include a reduced size clitoris and underdeveloped labia minora. Infrequently, the labia majora may also be underdeveloped. Some research has shown that females may experience vaginal atresia or haematocolpos.

The autosomal recessive form of the disorder tends to be much more severe. Examples of differences are summarized in the following table:

Jeune syndrome is a rare genetic disorder that affects the way a child’s cartilage and bones develop. It begins before the child is born. Jeune syndrome affects the child's rib cage, pelvis, arms and legs.

Usually, problems with the rib cage cause the most serious health problems for children with Jeune syndrome. Their rib cages (thorax) are smaller and narrower than usual. This can keep the child's lungs from developing fully or expanding when the child inhales. The child may breathe rapidly and shallowly. They may have trouble breathing when they have an upper or lower respiratory infection, like pneumonia.

Breathing trouble can range from mild to severe. In some children, it is not noticeable, aside from fast breathing. In most children, breathing problems are serious. About 60% to 70% of children with this condition die from respiratory failure as babies or young children.

Children with Jeune syndrome who survive often develop problems with their kidneys, another serious feature of Jeune syndrome. Over time they may experience renal failure.

As a result, few children with Jeune syndrome live into their teen years.

Children with Jeune syndrome have a form of dwarfism. They are short in stature, and their arms and legs are shorter than most people’s.

Another name for Jeune syndrome is asphyxiating thoracic dystrophy. This diagnosis is grouped with other chest problems called thoracic insufficiency syndrome (TIS).

The following signs are associated with the disease

- Abnormal heart development

- Abnormal skeletal development

- Hypermobile joints

- Large fingers

- Knock-knees

- Widely spaced teeth

- Bell-shaped chest (flared ribs)

- Compression of spinal cord

- Enlarged heart

- Dwarfism

- Heart murmur

- below average height for certain age

Patients with Morquio syndrome appear healthy at birth. They often present with spinal deformity, and there is growth retardation and possibly genu valgum in the second or third year of life. A patient with Morquio's syndrome is likely to die at an early age. Symptoms of the disease may include:

- Short stature and short neck (caused by flat vertebrae)

- Moderate kyphosis or scoliosis

- Mild pectus carinatum ("pigeon chest")

- Cervical spine: odontoid hypoplasia, atlanto-axial instability; may be associated with myelopathy with gradual loss of walking ability

- Joint laxity, mild dysostosis multiplex, dysplastic hips, large unstable knees, large elbows and wrists, and flat feet

- The combined abnormalities usually result in a duck-waddling gait

- Mid-face hypoplasia and mandibular protrusion

- Thin tooth enamel

- Corneal clouding

- Mild hepatosplenomegaly

Regarding the life span of people with Morquio, some can die as early as 2 or 3 years old, and some can live up to 60 or 70 years old. The oldest known person with Morquio syndrome type IV A was Kenneth D. Martin, who was born in Osage City, Kansas, USA and was 81 years old at the time of his death

Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, intelligence is typically normal.

The condition is either inherited from a person's parents or occurs as a new mutation. It is inherited in an autosomal dominant manner. It is due to a defect in the RUNX2 gene which is involved in bone formation. Diagnosis is suspected based on symptoms and X-rays with confirmation by genetic testing. Other conditions that can produce similar symptoms include mandibuloacral dysplasia, pyknodysostosis, osteogenesis imperfecta, and Hajdu-Cheney syndrome.

Treatment includes supportive measures such as a device to protect the skull and dental care. Surgery may be performed to fix certain bone abnormalities. Life expectancy is generally normal.

It affects about one per million people. Males and females are equally commonly affected. Modern descriptions of the condition date to at least 1896. The term is from "cleido" meaning collarbone, "cranial" meaning head, and "dysostosis" meaning formation of abnormal bone.

Robinow syndrome is an extremely rare genetic disorder characterized by short-limbed dwarfism, abnormalities in the head, face, and external genitalia, as well as vertebral segmentation. The disorder was first described in 1969 by human geneticist Meinhard Robinow, along with physicians Frederic N. Silverman and Hugo D. Smith, in the "American Journal of Diseases of Children". By 2002, over 100 cases had been documented and introduced into medical literature.

Two forms of the disorder exist, dominant and recessive, of which the former is more common. Patients with the dominant version often suffer moderately from the aforementioned symptoms. Recessive cases, on the other hand, are usually more physically marked, and individuals may exhibit more skeletal abnormalities. The recessive form is particularly frequent in Turkey. However, this can likely be explained by a common ancestor, as these patients' families can be traced to a single town in Eastern Turkey. Clusters of the autosomal recessive form have also been documented in Oman and Czechoslovakia.

The syndrome is also known as Robinow-Silverman-Smith syndrome, Robinow dwarfism, fetal face, fetal face syndrome, fetal facies syndrome, acral dysostosis with facial and genital abnormalities, or mesomelic dwarfism-small genitalia syndrome. The recessive form was previously known as Covesdem syndrome.

A dysostosis is a disorder of the development of bone, in particular affecting ossification.

Examples include craniofacial dysostosis, Klippel–Feil syndrome, and Rubinstein–Taybi syndrome.

It is one of the two categories of constitutional disorders of bone (the other being osteochondrodysplasia).

When the disorder involves the joint between two bones, the term "synostosis" is often used.

Asphyxiating thoracic dysplasia or Jeune syndrome is a ciliopathy.It is also known as "Jeune syndrome".

It was described in 1955.

A cervical rib in humans is an extra rib which arises from the seventh cervical vertebra. Sometimes known as "neck ribs", their presence is a congenital abnormality located above the normal first rib. A cervical rib is estimated to occur in 0.2% (1 in 500 people) to 0.5% of the population. People may have a cervical rib on the right, left or both sides.

Most cases of cervical ribs are not clinically relevant and do not have symptoms; cervical ribs are generally discovered incidentally. However, they vary widely in size and shape, and in rare cases, they may cause problems such as contributing to thoracic outlet syndrome, because of pressure on the nerves that may be caused by the presence of the rib.

A cervical rib represents a persistent ossification of the C7 lateral costal element. During early development, this ossified costal element typically becomes re-absorbed. Failure of this process results in a variably elongated transverse process or complete rib that can be anteriorly fused with the T1 first rib below.

On imaging, cervical ribs can be distinguished because their transverse processes are directed inferolaterally, whereas those of the adjacent thoracic spine are directed anterolaterally.

As a result of the changes to the developing embryo, the symptoms are very pronounced features, especially in the face. Low-set ears are a typical characteristic, as in all of the disorders which are called branchial arch syndromes. The reason for this abnormality is that ears on a foetus are much lower than those on an adult. During normal development, the ears "travel" upward on the head; however, in Crouzon patients, this pattern of development is disrupted. Ear canal malformations are extremely common, generally resulting in some hearing loss. In particularly severe cases, Ménière's disease may occur.

The most notable characteristic of Crouzon syndrome is craniosynostosis, as described above; however it usually presents as brachycephaly resulting in the appearance of a short and broad head. Exophthalmos (bulging eyes due to shallow eye sockets after early fusion of surrounding bones), hypertelorism (greater than normal distance between the eyes), and psittichorhina (beak-like nose) are also symptoms. Additionally, external strabismus is a common occurrence, which can be thought of as opposite from the eye position found in Down syndrome. Lastly, hypoplastic maxilla (insufficient growth of the midface) results in relative mandibular prognathism (chin appears to protrude despite normal growth of mandible) and gives the effect of the patient having a concave face. Crouzon syndrome is also associated with patent ductus arteriosus (PDA) and aortic coarctation.

For reasons that are not entirely clear, most Crouzon patients also have noticeably shorter humerus and femur bones relative to the rest of their bodies than members of the general population. A small percentage of Crouzon patients also have what is called "Type II" Crouzon syndrome, distinguished by partial syndactyly.

The condition is also known by various other names:

- Lateral facial dysplasia

- First and second branchial arch syndrome

- Oral-mandibular-auricular syndrome

- Otomandibular dysostosis

- Craniofacial microsomia

The Pai Syndrome is a rare subtype of frontonasal dysplasia. It is a triad of developmental defects of the face, comprising midline cleft of the upper lip, nasal and facial skin polyps and central nervous system lipomas. When all the cases are compared, a difference in severity of the midline cleft of the upper lip can be seen. The mild form presents with just a gap between the upper teeth. The severe group presents with a complete cleft of the upper lip and alveolar ridge.

Nervous system lipomas are rare congenital benign tumors of the central nervous system, mostly located in the medial line and especially in the corpus callosum. Generally, patients with these lipomas present with strokes. However, patients with the Pai syndrome don’t. That is why it is suggested that isolated nervous system lipomas have a different embryological origin than the lipomas present in the Pai syndrome. The treatment of CNS lipomas mainly consists of observation and follow up.

Skin lipomas occur relatively often in the normal population. However, facial and nasal lipomas are rare, especially in childhood. However, the Pai syndrome often present with facial and nasal polyps. These skin lipomas are benign, and are therefore more a cosmetic problem than a functional problem.

The skin lipomas can develop on different parts of the face. The most common place is the nose. Other common places are the forehead, the conjunctivae and the frenulum linguae. The amount of skin lipomas is not related to the severity of the midline clefting.

Patients with the Pai syndrome have a normal neuropsychological development.

Until today there is no known cause for the Pai syndrome.

The large variety in phenotypes make the Pai syndrome difficult to diagnose. Thus the incidence of Pai syndrome seems to be underestimated.

Thoracic insufficiency syndrome is the inability of the thorax to support normal respiration. It is frequently associated with chest and/or spinal abnormalities. Treatment options are limited, but include supportive pulmonary care and surgical options (thoracoplasty and/or implantation of vertical expandable prosthetic titanium rib (VEPTR) devices).

The presence of a cervical rib can cause a form of thoracic outlet syndrome due to compression of the lower trunk of the brachial plexus or subclavian artery. These structures become encroached upon by the cervical rib and scalene muscles.

Compression of the brachial plexus may be identified by weakness of the muscles around the muscles in the hand, near the base of the thumb. Compression of the subclavian artery is often diagnosed by finding a positive Adson's sign on examination, where the radial pulse in the arm is lost during abduction and external rotation of the shoulder. A positive Adson's sign is non-specific for the presence of a cervical rib however, as many individuals without a cervical rib will have a positive test.

Midfacial malformations can be subdivided into two different groups. One group with hypertelorism, this includes FND. The other with hypotelorism (a decreased distance between the eyes), this includes holoprosencephaly (failure of development of the forebrain). In addition, a facial cleft can be classified using the Tessier classification. Each of the clefts is numbered from 0 to 14. The 15 different types of clefts are then subdivided into 4 groups, based on their anatomical position in the face: midline clefts, paramedian clefts, orbital clefts and lateral clefts. FND is a midline cleft, classified as Tessier 0/14.

Besides this, the additional anomalies seen in FND can be subdivided by region. None of these anomalies are specific for the syndrome of FND, but they do occur more often in patients with FND than in the population. The anomalies that may be present are:

- Nasal: mild anomalies to nostrils that are far apart and a broad nasal root, a notch or cleft of the nose and accessory nasal tags.

- Ocular: narrowed eye slits, almond shaped eyes, epicanthal folds (extra eyelid tissue), epibulbar dermoids (benign tumors of the eye), upper eyelid colombas (full thickness upper eyelid defects), microphtalmos (one or two small eyes), congenital cataract and degeneration of the eye with retinal detachment.

- Facial: telecanthus (an increased distance between the corners of the eye), a median cleft of the upper lip and/or palatum, and a V-shaped hairline.

- Others: polydactyly (an excess of fingers or toes), syndactyly (fused fingers or toes), brachydactyly (short fingers and/or toes), clinodactyly (bending of the fifth fingers towards the fourth fingers), preauricular skin tags, an absent tragus, low set ears, deafness, small frontal sinuses, mental retardation, encephalocele (protrusion of the brain), spina bifida (split spine), meningoencephalocele (protrusion of both meninges), umbilical hernia, cryptorchidism (absence of one or two testes) and possibly cardiac anomalies.

The clefts of the face that are present in FND are vertical clefts. These can differ in severity. When they are less severe, they often present with hypertelorism and normal brain development.

Mental retardation is more likely when the hypertelorism is more severe or when extracephalic anomalies occur.

TOS affects mainly the upper limbs, with signs and symptoms manifesting in the shoulders, neck, arms and hands. Pain can be present on an intermittent or permanent basis. It can be sharp/stabbing, burning, or aching. TOS can involve only part of the hand (as in the pinky and adjacent half of the ring finger), all of the hand, or the inner aspect of the forearm and upper arm. Pain can also be in the side of the neck, the pectoral area below the clavicle, the armpit/axillary area, and the upper back (i.e., the trapezius and rhomboid area). Discoloration of the hands, one hand colder than the other hand, weakness of the hand and arm muscles, and tingling are commonly present.

TOS is often the underlying cause of refractory upper limb conditions like frozen shoulder and carpal tunnel syndrome that frequently defy standard treatment protocols. TOS can be related to Forward head posture.

A painful, swollen and blue arm, particularly when occurring after strenuous physical activity, could be the first sign of a subclavian vein compression related with an unknown TOS and complicated by thrombosis (blood clots), the so-called Paget–Schroetter syndrome or effort-induced thrombosis.

TOS can be related to cerebrovascular arterial insufficiency when affecting the subclavian artery. It also can affect the vertebral artery, in which case it could produce vision disturbances, including transient blindness, and embolic cerebral infarction.

TOS can also lead to eye problems and vision loss as a circumstance of vertebral artery compression. Although very rare, if compression of the brain stem is also involved in an individual presentation of TOS, transient blindness may occur while the head is held in certain positions.

If left untreated, TOS can lead to neurological deficits as a result of the hypoperfusion and hypometabolism of certain areas of the brain and cerebellum.

Franceschetti–Klein syndrome (also known as "Mandibulofacial dysostosis") is a syndrome that includes palpebral antimongoloid fissures, hypoplasia of the facial bones, macrostomia, vaulted palate, malformations of both the external and internal ear, buccal-auricular fistula, abnormal development of the neck with stretching of the cheeks, accessory facial fissures, and skeletal deformities.

It is sometimes equated with Treacher Collins syndrome.

Scheuermann's disease is considered to be a form of juvenile osteochondrosis of the spine. It is found mostly in teenagers and presents a significantly worse deformity than postural kyphosis. Patients suffering with Scheuermann’s kyphosis cannot consciously correct their posture. The apex of their curve, located in the thoracic vertebrae, is quite rigid.

Scheuermann's disease is notorious for causing lower and mid-level back and neck pain, which can be severe and disabling. The sufferer may feel pain at the apex of the curve, which is aggravated by physical activity and by periods of standing or sitting; this can have a significantly detrimental effect to their lives as their level of activity is curbed by their disability. The sufferer may feel isolated or uneasy amongst their peers if they are children, depending on the level of deformity.

In addition to the pain associated with Scheuermann's disease, many sufferers of the disorder have loss of vertebral height, and depending on where the apex of the curve is, may have a visual 'hunchback' or 'roundback'. It has been reported that curves in the lower thoracic region cause more pain, whereas curves in the upper region present a more visual deformity. Nevertheless, it is typically pain or cosmetic reasons that prompt sufferers to seek help for their condition. In studies, kyphosis is better characterized for the thoracic spine than for the lumbar spine.

The seventh and tenth thoracic vertebrae are most commonly affected. It causes backache and spinal curvature. In very serious cases it may cause internal problems and spinal cord damage, but these cases are extremely rare. The curvature of the back decreases height, thus putting pressure on internal organs, wearing them out more quickly than the natural aging process; surgical procedures are almost always recommended in this case.

Crouzon syndrome is an autosomal dominant genetic disorder known as a branchial arch syndrome. Specifically, this syndrome affects the first branchial (or pharyngeal) arch, which is the precursor of the maxilla and mandible. Since the branchial arches are important developmental features in a growing embryo, disturbances in their development create lasting and widespread effects.

This syndrome is named after Octave Crouzon, a French physician who first described this disorder. He noted the affected patients were a mother and her daughter, implying a genetic basis. First called "craniofacial dysostosis", the disorder was characterized by a number of clinical features. This syndrome is caused by a mutation in the fibroblast growth factor receptor II, located on chromosome 10.

Breaking down the name, "craniofacial" refers to the skull and face, and "dysostosis" refers to malformation of bone.

Now known as Crouzon syndrome, the characteristics can be described by the rudimentary meanings of its former name. What occurs is that an infant's skull and facial bones, while in development, fuse early or are unable to expand. Thus, normal bone growth cannot occur. Fusion of different sutures leads to different patterns of growth of the skull.

Examples include: trigonocephaly (fusion of the metopic suture), brachycephaly (fusion of the coronal suture), dolichocephaly (fusion of the sagittal suture), plagiocephaly (unilateral premature closure of lambdoid and coronal sutures), oxycephaly (fusion of coronal and lambdoidal sutures), Kleeblattschaedel (premature closure of all sutures).