Common signs of Say–Meyer syndrome are trigonocephaly as well as head and neck symptoms. The head and neck symptoms come in the form of craniosynostosis affecting the metopic suture (the dense connective tissue structure that divides the two halves of the skull in children which usually fuse together by the age of six). Symptoms of Say–Meyer syndrome other than developmental delay and short stature include

- Intellectual disability.

- Low-set ears/posteriorly rotated ears

- Intellectual deficit as well as learning disability

- Intrauterine growth retardation (poor growth of a baby while it is in the mother's womb)

- Posterior fontanel

- Premature synostosis of the lambdoid suture (the fusion of the bones to the joint is premature)

- Narrow forehead

- Trigonocephaly (a frontal bone anomaly that is characterized by a premature fusion of the bones which gives the forehead a triangular shape)

- Hypotelorism or hypertelorism (reduced or increased width between the eyes)

- Craniosynostosis (when one or more seam-like junctions between two bones fuses by turning into bone. This changes the growth pattern of the skull)

- Low birth weight and height

The affected patients sometimes show a highly arched palate, clinodactyly (a defect in which toes or fingers are positioned abnormally) and ventricular septal defect (a heart defect that allows blood to pass directly from left to the right ventricle which is caused by an opening in the septum). Overall, Say–Meyer syndrome impairs growth, motor function, and mental state.

It is a disorder that is mostly characterized as developmental delay and short stature. Magnetic resonance imaging scans usually reveal that there is a decreased volume of white matter in the bilateral cerebral hemispheres, a brain stem that is smaller in size, and a thin corpus callosum (nerve fibers that connect the two hemispheres of the brain). The syndrome is one of the rare causes of short stature.

Diagnosis can be characterized by typical facial and cranial deformities.

Observatory signs of trigonocephaly are:

- a triangular shaped forehead seen from top view leading to a smaller anterior cranial fossa

- a visible and palpable midline ridge

- hypotelorism inducing ethmoidal hypoplasia

Imaging techniques (3D-CT, Röntgenography, MRI) show:

- epicanthal folds in limited cases

- teardrop shaped orbits angulated towards the midline of the forehead ('surprised coon' sign) in severe cases

- a contrast difference between a röntgenograph of a normal and a trigonocephalic skull

- anterior curving of the metopic suture seen from lateral view of the cranium on a röntgenograph

- a normal cephalic index (maximum cranium width / maximum cranium length) however, there is bitemporal shortening and biparietal broadening

The neuropsychological development is not always affected. These effects are only visible in a small percentage of children with trigonocephaly or other suture synostoses. Neuropsychological signs are:

- problems in behaviour, speech and language

- mental retardation

- neurodevelopmental delays such as ADHD (Attention Deficit Hyperactivity Disorder), ODD (Oppositional Defiant Disorder), ASD (Autism Spectrum Disorder) and CD (Conduct Disorder). Many of these delays become evident at school age.

Trigonocephaly (Greek: 'trigonon' = triangle, 'kephale' = head) is a congenital condition of premature fusion of the metopic suture (Greek: 'metopon' = forehead) leading to a triangular shaped forehead. The merging of the two frontal bones leads to transverse growth restriction and parallel growth expansion. It may occur syndromic involving other abnormalities or isolated.

The joint changes include hyperextensibility (double-jointedness) and arthritis. Babies and young children with Stickler syndrome usually have very hyperextensible joints. As an affected child gets older, they may experience pain and stiffness from overuse of a joint. Osteoarthritis of the large joints often develops during the third or fourth decade. The joint changes in Marshall syndrome are of the same type but to a lesser degree. There also may be changes in the bones that show up on X-ray but generally are not a problem.

The most severe problem associated with Stickler syndrome is Pierre Robin syndrome. This refers to a cleft palate resulting from a very small lower jaw. During early fetal life, the roof of the mouth is normally open and the sides of the palate have to come together to close. If the jaw is too small, there is not enough room for the tongue which is then pushed up and gets in the way of the closing palate. Sometimes the chin is so small the baby has problems with eating and breathing if the tongue blocks the back of the throat. Cleft palate is found less frequently in Marshall Syndrome than in Stickler syndrome but still more frequently than in the general population.

The facial features of Marshall Syndrome include a flat midface, the appearance of large eyes, short upturned nose, and a round face. The facial features of Stickler syndrome are less prominent but include a rather long flat face, and depressed nasal bridge.

It is characterized by developmental defects including cryptophthalmos (where the eyelids fail to separate in each eye), and malformations in the genitals (such as micropenis, cryptorchidism or clitoromegaly). Congenital malformations of the nose, ears, larynx and renal system, as well as mental retardation, manifest occasionally. Syndactyly (fused fingers or toes) has also been noted.

Thumb hypoplasia is a spectrum of congenital abnormalities of the thumb varying from small defects to absolute retardation of the thumb. It can be isolated, when only the thumb is affected, and in 60% of the cases it is associated with radial dysplasia (or radial club, radius dysplasia, longitudinal radial deficiency). Radial dysplasia is the condition in which the forearm bone and the soft tissues on the thumb side are underdeveloped or absent.

In an embryo the upper extremities develop from week four of the gestation. During the fifth to eighth week the thumb will further develop. In this period something goes wrong with the growth of the thumb but the exact cause of thumb hypoplasia is unknown.

One out of every 100,000 live births shows thumb hypoplasia. In more than 50% of the cases both hands are affected, otherwise mainly the right hand is affected.

About 86% of the children with hypoplastic thumb have associated abnormalities. Embryological hand development occurs simultaneously with growth and development of the cardiovascular, neurologic and hematopoietic systems. Thumb hypoplasia has been described in 30 syndromes wherein those abnormalities have been seen. A syndrome is a combination of three or more abnormalities. Examples of syndromes with an hypoplastic thumb are Holt-Oram syndrome, VACTERL association and thrombocytopenia absent radius (TAR syndrome).

In general there are five types of thumb hypoplasia, originally described by Muller in 1937 and improved by Blauth, Buck-Gramcko and Manske.

- Type I: the thumb is small, normal components are present but undersized. Two muscles of the thumb, the abductor pollicis brevis and opponens pollicis, are not fully developed

. This type requires no surgical treatment in most cases.

- Type II is characterized by a tight web space between the thumb and index finger which restricts movement, poor thenar muscles and an unstable middle joint of the thumb metacarpophalangeal joint. This unstable thumb is best treated with reconstruction of the mentioned structures.

- Type III thumbs are subclassified into two subtypes by Manske. Both involve a less developed first metacarpal and a nearly absent thenar musculature. Type III-A has a fairly stable carpometacarpal joint and type III-B does not. The function of the thumb is poor. Children with type III are the most difficult patients to treat because there is not one specific treatment for the hypoplastic thumb. The limit between pollicization and reconstruction varies. Some surgeons have said that type IIIA is amenable to reconstruction and not type IIIB. Others say type IIIA is not suitable for reconstruction too. Based on the diagnosis the doctor has to decide what is needed to be done to obtain a more functional thumb, i.e. reconstruction or pollicization. In this group careful attention should be paid to anomalous tendons coming from the forearm (extrinsic muscles, like an aberrant long thumb flexor – flexor pollicis longus).

- Type IV is called a pouce flottant, floating thumb. This thumb has a neurovascular bundle which connects it to the skin of the hand. There’s no evidence of thenar muscles and rarely functioning tendons. It has a few rudimentary bones. Children with type IV are difficult to reconstruct. This type is nearly always treated with an index finger pollicization to improve hand function.

- Type V is no thumb at all and requires pollicization.

Fraser syndrome (also known as Meyer-Schwickerath's syndrome, Fraser-François syndrome, or Ullrich-Feichtiger syndrome) is an autosomal recessive congenital disorder. Fraser syndrome is named for the geneticist George R. Fraser, who first described the syndrome in 1962.

Some of the different types of AMC include:

- Arthrogryposis multiplex due to muscular dystrophy.

- Arthrogryposis ectodermal dysplasia other anomalies, also known as Cote Adamopoulos Pantelakis syndrome, Trichooculodermovertebral syndrome, syndrome and Alves syndrome.

- Arthrogryposis epileptic seizures migrational brain disorder.

- Arthrogryposis thoracic dystrophy, also known as Van Bervliet syndrome.

- Arthrogryposis like disorder, also known as Kuskokwim disease.

- Arthrogryposis-like hand anomaly and sensorineural deafness.

- Arthrogryposis multiplex congenita calcification.

- Arthrogryposis multiplex congenita distal (), also known as X-linked spinal muscular atrophy type 2

- Gordon Syndrome, also known as Distal Arthrogryposis, Type 2A.

- Arthrogryposis multiplex congenita, distal type 2B, also known as Freeman-Sheldon syndrome variant.

- Arthrogryposis multiplex congenita neurogenic type (). This particular type of AMC has been linked to the gene on locus 5q35. Arthrogryposis multiplex congenita pulmonary hypoplasia, also with a large number of synonyms.

- Arthrogryposis multiplex congenita whistling face, also known as Illum syndrome.

- Arthrogryposis multiplex congenita, distal type 1 ().

- Arthrogryposis ophthalmoplegia retinopathy, also known as Oculomelic amyoplasia.

- Arthrogryposis renal dysfunction cholestasis syndrome, also known as Syndrome.

Often, every joint in a patient with arthrogryposis is affected; in 84% all limbs are involved, in 11% only the legs, and in 4% only the arms are involved. Every joint in the body, when affected, displays typical signs and symptoms: for example, the shoulder (internal rotation); wrist (volar and ulnar); hand (fingers in fixed flexion and thumb in palm); hip (flexed, abducted and externally rotated, frequently dislocated); elbow (extension and pronation) and foot (clubfoot). Range of motion can be different between joints because of the different deviations. Some types of arthrogryposis like amyoplasia have a symmetrical joint/limb involvement, with normal sensations. The contractures in the joints can result in delayed walking development in the first 5 years, but severity of contractures do not necessarily predict eventual walking ability or inability.

Intelligence is normal to above normal in children with amyoplasia, but it is not known how many of these children have an above normal intelligence, and there is no literature available about the cause of this syndrome. There are a few syndromes like the Freeman-Sheldon and Gordon syndrome, which have craniofacial involvement. The amyoplasia form of arthrogryposis is sometimes accompanied with a midline facial hemangioma.

Arthrogryposis is not a diagnosis but a clinical finding, so this disease is often accompanied with other syndromes or diseases. These other diagnoses could affect any organ in a patient. There are a few slightly more common diagnoses such as pulmonary hypoplasia, cryptorchidism, congenital heart defects, tracheoesophageal fistulas, inguinal hernias, cleft palate, and eye abnormalities.

Say syndrome is a condition characterized by bilateral acromial dimples.

Urban–Rogers–Meyer syndrome, also known as Prader–Willi habitus, osteopenia, and camptodactyly or Urban syndrome, is an extremely rare inherited congenital disorder first described by Urban et al. (1979). It is characterized by genital anomalies, mental retardation, obesity, contractures of fingers, and osteoporosis, though further complications are known.

Characteristic injuries associated with AHT include retinal bleeds, multiple fractures of the long bones, and subdural hematomas (bleeding in the brain). These signs have evolved through the years as the accepted and recognized signs of child abuse. Medical professionals strongly suspect shaking as the cause of injuries when a young child presents with retinal bleed, fractures, soft tissue injuries or subdural hematoma, that cannot be explained by accidental trauma or other medical conditions.

Retinal bleeds occur in around 85% of AHT cases; the type of retinal bleeds are particularly characteristic of this condition, making the finding useful in establishing the diagnosis. While there are many other causes of retinal bleeds besides AHT, there are usually additional findings (eyes or systemic) which make the alternative diagnoses apparent.

Fractures of the vertebrae, long bones, and ribs may also be associated with AHT. Dr. John Caffey reported in 1972 that metaphyseal avulsions (small fragments of bone had been torn off where the periosteum covering the bone and the cortical bone are tightly bound together) and "bones on both the proximal and distal sides of a single joint are affected, especially at the knee".

People after AHT may display irritability, failure to thrive, alterations in eating patterns, lethargy, vomiting, seizures, bulging or tense fontanels (the soft spots on a baby's head), increased size of the head, altered breathing, and dilated pupils.

Abusive head trauma (AHT), commonly known as shaken baby syndrome (SBS), is an injury to a child's head caused by someone else. Symptoms may range from subtle to obvious. Symptoms may include vomiting or a baby that will not settle. Often there are no visible signs of trauma. Complications include seizures, visual impairment, cerebral palsy, and cognitive impairment.

The cause may be blunt trauma or vigorous shaking. Often this occurs as a result of a caregiver becoming frustrated due to the child crying. Diagnosis can be difficult as symptoms may be nonspecific. A CT scan of the head is typically recommended if a concern is present. While retinal bleeding is common, it can also occur in other conditions. Abusive head trauma is a type of child abuse.

Educating new parents appears to be beneficial in decreasing rates of the condition. Treatment occasionally requires surgery, such as to place a cerebral shunt. AHT is estimated to occur in 3 to 4 per 10,000 babies a year. It occurs most frequently in those less than five years of age. The risk of death is about 25%. The diagnosis may also carry legal consequences for the parents.

Stiff skin syndrome (also known as "Congenital fascial dystrophy") is a cutaneous condition characterized by ‘rock hard’ induration, thickening of the skin and subcutaneous tissues, limited joint mobility, and mild hypertrichosis in infancy or early childhood. Immunologic abnormalities or vascular hyperactivity are not present in patients.

Not much is known about it, cause or treatment, as it has only been reported 41 times throughout history. Not much is known about this, and further investigation is required.According to news reports on one particular patient by name of Jaiden Rogers, the patient's skin hardens in some places, and it slowly spreads over the surrounding area. For Rogers, it's spreading over the back, legs, and hips, inhibiting his ability to walk. He say it hurts, but finds it difficult to describe the sensations further. Currently, it appears that chemotherapy similar to that used for cancer is slowing the spread, but it also appears that once the skin has hardened it cannot revert to its healthy flexible state. Physical therapy also appears to help. Further investigation is required.

Adenoid hypertrophy (or enlarged adenoids) is the unusual growth ("hypertrophy") of the adenoid tonsil first described by the Danish physician Wilhelm Meyer (1824-1895) in Copenhagen in 1868. He described that a long term adenoid hypertrophy will cause an obstruction of the nasal airways. These will lead to a dentofacial growth anomaly that was defined as "adenoid facies" (see long face syndrome).

There is very little lymphoid tissue in the nasopharynx of young babies; humans are born without substantial adenoids. The mat of lymphoid tissue called adenoids starts to get sizable during the first year of life. Just how big the adenoids become is quite variable between individual children.

Nasopalatine duct cysts usually present as asymptomatic palatal swellings, but they may rarely be accompanied by pain and/or purulent discharge. The cysts are generally treated by .

Symptoms typically begin in childhood and are progressive, often resulting in death by early adulthood. Symptoms of PKAN begin before middle childhood, and most often are noticed before ten years of age. Symptoms include:

- dystonia (repetitive uncontrollable muscle contractions that may cause jerking or twisting of certain muscle groups)

- dysphagia & dysarthria due to muscle groups involved in speech being involved

- rigidity/stiffness of limbs

- tremor

- writhing movements

- dementia

- spasticity

- weakness

- seizures (rare)

- toe walking

- retinitis pigmentosa, another degenerative disease that affects the individual’s retina, often causing alteration of retinal color and progressive deterioration of the retina at first causing night blindness and later resulting in a complete loss of vision.

25% of individuals experience an uncharacteristic form of PKAN that develops post-10 years of age and follows a slower, more gradual pace of deterioration than those pre-10 years of age. These individuals face significant speech deficits as well as psychiatric and behavioral disturbances.

Being a progressive, degenerative nerve illness, PKAN leads to early immobility and often death by early adulthood. Death occurs prematurely due to infections such as pneumonia, and the disease in itself is technically not life limiting.

Children with a tic disorder may exhibit the following symptoms:

- overwhelming urge to make movement

- jerking of arms

- clenching of fists

- excessive eye blinking

- shrugging of shoulders

- kicking

- raising eyebrows

- flaring of nostrils

- production of repetitive noises such as grunting, clicking, moaning, snorting, squealing, or throat clearing

The nasopalatine cyst is the most common non-odontogenic cyst of the oral cavity, at an estimated occurrence rate of 73%.

Enlarged adenoids can become nearly the size of a ping pong ball and completely block airflow through the nasal passages. Even if enlarged adenoids are not substantial enough to physically block the back of the nose, they can obstruct airflow enough so that breathing through the nose requires an uncomfortable amount of work, and inhalation occurs instead through an open mouth. Adenoids can also obstruct the nasal airway enough to affect the voice without actually stopping nasal airflow altogether.

Nasal blockage is determined by at least two factors: 1) the size of the adenoids, and 2) the size of the nasal pharynx passageway.

The adenoid usually reaches its greatest size by about age 5 years or so, and then fades away ("atrophies") by late childhood - generally by the age of 7 years. The lymphoid tissue remains under the mucosa of the nasopharynx, and could be seen under a microscope if the area was biopsied, but the mass is so reduced in size that the roof of the nasopharynx becomes flat rather than mounded. Just as the size of the adenoids is variable between individuals, so is the age at which adenoids atrophy.

The symptoms caused by enlarged adenoids are mostly due to "where" this lymphoid tissue is located. The adenoids are in the midline of the nasopharynx, and the Eustachian tubes open from either ear to the right and left of them. In children with excessive middle ear infections and chronic middle ear fluid, there is a high bacterial count in the adenoids as compared to children without problematic otitis media, even if the size of the adenoids is small. The adenoids in these cases provides a reservoir of pathogenic bacteria that cause ear infections and subsequent middle ear effusions (fluid).

The nasopharynx lies right above the throat. Splashes of excessive "drip" from infected adenoids may land directly on the vocal cords. Although the larynx and vocal cords do not ordinarily become infected from adenoiditis, their mucosa does become irritated. The vocal cords are extremely sensitive to touch, and any fluid drops falling on them cause an irresistible urge to cough. Adenoiditis therefore is one of the causes of cough.

Benign Rolandic epilepsy or benign childhood epilepsy with centrotemporal spikes (BCECTS) is the most common epilepsy syndrome in childhood. Most children will outgrow the syndrome (it starts around the age of 3-13 with a peak around 8–9 years and stops around age 14-18), hence the label benign. The seizures, sometimes referred to as "sylvian seizures", start around the central sulcus of the brain (also called the centrotemporal area, located around the Rolandic fissure, after Luigi Rolando).

Pantothenate kinase-associated neurodegeneration (PKAN), also known as neurodegeneration with brain iron accumulation 1 (NBIA1), also called Hallervorden–Spatz syndrome, is a degenerative disease of the brain that can lead to parkinsonism, dystonia, dementia, and ultimately death. Neurodegeneration in PKAN is accompanied by an excess of iron that progressively builds up in the brain.