Numerous associated abnormalities of other organ systems may be present. This heterogeneity requires comprehensive evaluation of all patients and treatment regimes that can vary from modification of activities to extensive spinal surgeries. Furthermore, it is unclear whether Klippel–Feil syndrome is a unique disease, or if it is one part of a spectrum of congenital spinal deformities. Klippel–Feil syndrome is usually diagnosed after birth.

The most common sign of the disorder is restricted mobility of the neck and upper spine. A short neck and low hairline at the back of the head may occur in some patients.

Associated abnormalities may include:

- scoliosis (side-to-side curvature of the spine), which is abnormal curving of the spine. The spine sometimes appears as a "C" or an "S"

- spina bifida, when the spinal canal and the back bone do not close completely during birth

- anomalies of the kidneys and the ribs

- cleft palate (hole in the roof of the mouth)

- dental problems (late dentition, high-risk of caries, oligo- and hypodontia)

- respiratory problems

- heart malformations

- short stature

- Duane syndrome

- Approximately 35% of patients with Klippel–Feil syndrome will also have a congenital elevation of the scapula known as Sprengel's deformity

The disorder also may be associated with abnormalities of the head and face, skeleton, sex organs, muscles, brain and spinal cord, arms, legs, fingers and heart defects. These heart defects often lead to a shortened life expectancy, the average being 35–45 years of age among males and 40–50 among females. This condition is similar to the heart failure seen in gigantism.

In 2011, a study identifying the occurrence of symptoms of 100 patients was published.

Sufferers usually have long, thin fingers and toes with contractures preventing straightening and limiting movement. Contractures also affect hips, elbows, knees and ankles. They also have unusual external ears that appear crumpled. Contractures may be present from birth and may appear as a club foot. Long bone fractures may also form a part of the syndrome, though the evidence for this is limited to the case report level.

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.

This syndrome is characterised by typical facial appearance, slight build, thin and translucent skin, severely adducted thumbs, arachnodactyly, club feet, joint instability, facial clefting and bleeding disorders, as well as heart, kidney or intestinal defects. Severe psychomotor and developmental delay and decreased muscle tone may also be present during infancy. Cognitive development during childhood is normal.

Most of the signs of MWS are present during the neonatal period. The most common signs at this state are multiple congenital joint contractures, dysmorphic features with mask-like face, blepharophimosis, ptosis, micrognathia, cleft or high arched palate, low-set ears, arachnodactyly, chest deformation as pectus, kyphoscoliosis and absent deep tendon reflexes are frequent minor malformations have also been described and consist of renal anomalies, cardiovascular abnormalities, hypospadias, omphalomesenteric duct, hypertriphic pyloric stenosis, duodenal bands, hyoplastic right lower lobe of the lung, displacement of the larynx to the right and vertebral abnormalities, cerebral malformations.

- 75% of children with MWS have blepharophimosis, small mouth, micrognathia, kyphosis/scoliosis, radio ulnar synostose and multiple contractures.

- They have severe developmental delay; congenital joint contractures and blepharophimosis should be present in every patient

- 2 out of 3 of the following signs should be manifested: post natal growth, mask-like faces, retardation, and decreased muscular mass.

- Some may require additional signs such as; micrognathia, high arched or cleft palate, low set ears, kyphoscoliosis.

- The symptoms of MWS are normally diagnosed during the newborn period

This syndrome is associated with microcephaly, arthrogryposis and cleft palate and various craniofacial, respiratory, neurological and limb abnormalities, including bone and joint defects of the upper limbs, adducted thumbs, camptodactyly and talipes equinovarus or calcaneovalgus. It is characterized by craniosynostosis, and myopathy in association with congenital generalized hypertrichosis.

Patients with the disease are considered intellectually disabled. Most die in childhood. Patients often suffer from respiratory difficulties such as pneumonia, and from seizures due to dysmyelination in the brain's white matter. It has been hypothesized that the Moro reflex (startle reflex in infants) may be a tool in detecting the congenital clapsed thumb early in infancy. The thumb normally extends as a result of this reflex.

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 natural history of MWS is not well known: many patients died in infancy and clinical follow-up has been reported in few surviving adults. However, diagnosis may be more difficult to establish in adults patients, such as: blepharophimosis, contractures, growth retardation, and developmental delay, whereas minor face anomalies are less noticeable as the patient grows older. Throughout the development of the patient from young child to older adult changes the behavior drastically, from kindness to restless and hyperactive to aggressive.

Chief markers of Goldenhar syndrome are incomplete development of the ear, nose, soft palate, lip, and mandible on usually one side of the body. Additionally, some patients will have growing issues with internal organs, especially heart, kidneys, and lungs. Typically, the organ will either not be present on one side or will be underdeveloped. Note that while it is more usual for there to be problems on only one side, it has been known for defects to occur bilaterally (approximate incidence 10% of confirmed GS cases).

Other problems can include severe scoliosis (twisting of the vertebrae), limbal dermoids, and hearing loss (see hearing loss with craniofacial syndromes), and deafness or blindness in one or both ears/eyes, Granulosa cell tumors may be associated as well.

Klippel–Feil syndrome is a rare disease, initially reported in 1884 by Maurice Klippel and André Feil from France, characterized by the congenital fusion of any two of the seven cervical vertebrae.

The syndrome occurs in a heterogeneous group of patients unified only by the presence of a congenital defect in the formation or segmentation of the cervical spine. Klippel-Feil results in limited movement of the neck. Klippel–Feil syndrome is sometimes identified by shortness of the neck, but not all people with this disorder have a visibly shortened neck. Some people with the syndrome have a very low hairline.

In 1919, in his PhD thesis, André Feil suggested another classification of the syndrome encompassing not only deformation of the cervical spine but also deformation of the lumbar and thoracic spine.

Beals syndrome (congenital contractural arachnodactyly, Beals–Hecht syndrome) is a rare congenital connective tissue disorder. Beals syndrome has only recently been described as a syndrome distinct from Marfan's syndrome. Ricky Berwick is an internet star with this disease.

It was characterized in 1972.

It is associated with FBN2.

It is caused by a mutation in FBN2 gene on chromosome 5q23. Contractures of varying degrees at birth, mainly involving the large joints, are present in all affected children. Elbows, knees and fingers are most commonly involved. The contractures may be mild and tend to reduce in severity, but residual camptodactyly always remains present. The arm span exceeds body height but the discrepancy may be underestimated due to contractures of elbows and fingers. The same holds for the lower body portion with knee contractures. The most serious complication in CCA is scoliosis and sometimes kyphoscoliosis mandating surgery.

Because collagen plays an important role in the development of the body, people with Kniest Dysplasia will typically have their first symptoms at birth. These symptoms can include:.

- Musculoskeletal Problems

- Short limbs

- Shortened body trunk

- Flattened bones in the spine

- kyphoscoliosis

- Scoliosis (Lateral curvature of the spine)

- Early development of arthritis

- Respiratory problems

- Respiratory tract infection

- Difficulty breathing

- Eye problems

- Severe myopia (near-sightedness)

- Cataract (cloudiness in the lens of the eye)

- Hearing problems

- progressive hearing loss

- ear infections

Most symptoms are chronic and will continue to worsen as the individual ages. It is essential to have regular checkups with general doctors, orthopedist, ophthalmologists, and/or otorhinolaryngologists. This will help to detect whether there are any changes that could cause concern.

Goldenhar syndrome (also known as oculo-auriculo-vertebral (OAV) syndrome) is a rare congenital defect characterized by incomplete development of the ear, nose, soft palate, lip, and mandible. It is associated with anomalous development of the first branchial arch and second branchial arch. Common clinical manifestations include limbal dermoids, preauricular skin tags, and strabismus.

The term is sometimes used interchangeably with hemifacial microsomia, although this definition is usually reserved for cases without internal organ and vertebrae disruption.

It affects between 1/3,500 and 1/26,000 live births, with a male:female ratio of 3:2.

Antley–Bixler syndrome presents itself at birth or prenatally. Features of the disorder include brachycephaly (flat forehead), craniosynostosis (complete skull-joint closure) of both coronal and lambdoid sutures, facial hypoplasia (underdevelopment); bowed ulna (forearm bone) and femur (thigh bone), synostosis of the radius (forearm bone), humerus (upper arm bone), and trapezoid (hand bone); camptodactyly (fused interphalangeal joints in the fingers), thin ilial wings (outer pelvic plate), and renal malformations.

Other symptoms, such as cardiac malformations, proptotic exophthalmos (bulging eyes), arachnodactyly (spider-like fingers), as well as nasal, anal, and vaginal atresia (occlusion) have been reported.

Arachnodactyly ("spider fingers") or achromachia is a condition in which the fingers and toes are abnormally long and slender, in comparison to the palm of the hand and arch of the foot. Also, the individual's thumbs tend to also be pulled inwards towards the palm. It can be present at birth or develop in later life.

Among the signs and symptoms demonstrated, by this condition are the following:

- Arachnodactyly

- Congenital diaphragmatic hernia

- Mental dysfunction

- Keratoconus

- Aortic regurgitation

- Blepharophimosis

This feature can occur on its own, with no underlying health problems. However, it can also be associated with certain medical conditions. Examples include Marfan syndrome, Ehlers-Danlos syndrome, Loeys–Dietz syndrome, congenital contractural arachnodactyly, and homocystinuria.

Arachnodactyly has been linked to mutations in both fibrillin-1 and fibrillin-2 genes.

As of 2017 there are 13 types of Ehlers-Danlos syndromes, with a significant overlap in features.

Hypermobile EDS - characterized primarily by joint hypermobility affecting both large and small joints, which may lead to recurrent joint dislocations and subluxations (partial dislocation). In general, people with this type have soft, smooth and velvety skin with easy bruising and chronic pain of the muscles and/or bones.

Classical EDS - associated with extremely elastic (stretchy), smooth skin that is fragile and bruises easily; wide, atrophic scars (flat or depressed scars); and joint hypermobility. Molluscoid pseudotumors (calcified hematomas over pressure points such as the elbow) and spheroids (fat-containing cysts on forearms and shins) are also frequently seen. Hypotonia and delayed motor development may occur.

Vascular EDS - characterized by thin, translucent skin that is extremely fragile and bruises easily. Arteries and certain organs such as the intestines and uterus are also fragile and prone to rupture. People with this type typically have short stature; thin scalp hair; and characteristic facial features including large eyes, a thin nose, and lobeless ears. Joint hypermobility is present, but generally confined to the small joints (fingers, toes). Other common features include club foot; tendon and/or muscle rupture; acrogeria (premature aging of the skin of the hands and feet); early onset varicose veins; pneumothorax (collapse of a lung); recession of the gums; and a decreased amount of fat under the skin.

Kyphoscoliosis EDS - associated with severe hypotonia at birth, delayed motor development, progressive scoliosis (present from birth), and scleral fragility. Affected people may also have easy bruising; fragile arteries that are prone to rupture; unusually small corneas; and osteopenia (low bone density). Other common features include a "marfanoid habitus" which is characterized by long, slender fingers (arachnodactyly); unusually long limbs; and a sunken chest (pectus excavatum) or protruding chest (pectus carinatum).

Arthrochalasia EDS - characterized by severe joint hypermobility and congenital hip dislocation. Other common features include fragile, elastic skin with easy bruising; hypotonia; kyphoscoliosis (kyphosis and scoliosis); and mild osteopenia.

Dermatosparaxis EDS - associated with extremely fragile skin leading to severe bruising and scarring; saggy, redundant skin, especially on the face; and hernias.

Brittle Cornea Syndrome (BCS) characterized by thin cornea, early onset progressive keratoglobus; and blue sclerae.

Classical-like EDS (clEDS) characterized by skin hyperextensibility with velvety skin texture and absence of atrophic scarring, generalized joint hypermobility (GJH) with or without recurrent dislocations (most often shoulder and ankle), and easily bruised skin or spontaneous ecchymoses (discolorations of the skin resulting from bleeding underneath).

Spondylodysplastic EDS (spEDS) characterized by short stature (progressive in childhood), muscle hypotonia (ranging from severe congenital, to mild later-onset), and bowing of limbs.

Musculocontractural EDS (mcEDS) characterized by congenital multiple contractures, characteristically adduction-flexion contractures and/or talipes equinovarus (clubfoot), characteristic craniofacial features, which are evident at birth or in early infancy, and skin features such as skin hyperextensibility, easy bruisability, skin fragility with atrophic scars, increased palmar wrinkling.

Myopathic EDS (mEDS) characterized by congenital muscle hypotonia, and/or muscle atrophy, that improves with age, Proximal joint contractures (joints of the knee, hip and elbow); and hypermobility of distal joints (joints of the ankles, wrists, feet and hands).

Periodontal EDS (pEDS) characterized by severe and intractable periodontitis of early onset (childhood or adolescence), lack of attached gingiva, pretibial plaques; and family history of a first-degree relative who meets clinical criteria.

Cardiac-valvular EDS (cvEDS) characterized by severe progressive cardiac-valvular problems (aortic valve, mitral valve), skin problems (hyperextensibility, atrophic scars, thin skin, easy bruising) and joint hypermobility (generalized or restricted to small joints).

Prune-belly triad consists of: Cryptorchidism, abdominal wall defects and genitourinary defects:

- A partial or complete lack of abdominal wall muscles. There may be wrinkly folds of skin covering the abdomen.

- Cryptorchidism (undescended testicles) in males

- Urinary tract abnormality such as unusually large ureters, distended bladder, accumulation and backflow of urine from the bladder to the ureters and the kidneys (vesicoureteral reflux)

Other Symptoms include:

- Frequent urinary tract infections due to the inability to properly expel urine.

- Ventricular septal defect

- Malrotation of the gut

- Club foot

- Later in life, a common symptom is post-ejaculatory discomfort. Most likely a bladder spasm, it lasts about two hours.

- Musculoskeletal abnormalities include pectus excavatum, scoliosis, and congenital joint dislocations including the hip. Diagnosis of prune belly syndrome necessitates a thorough orthopaedic evaluation because of the high prevalence of associated musculoskeletal abnormalities.

Pectus carinatum is an overgrowth of costal cartilage causing the sternum to protrude forward. It primarily occurs among four different patient groups, and males are more frequently affected than females. Most commonly, pectus carinatum develops in 11-to-14-year-old pubertal males undergoing a growth spurt. Some parents report that their child's pectus carinatum seemingly popped up overnight. Second most common is the presence of pectus carinatum at or shortly after birth. The condition may be evident in newborns as a rounded anterior chest wall. As the child reaches age 2 or 3 years of age, the outward sternal protrusion becomes more pronounced. Pectus carinatum can also be caused by vitamin D deficiency in children (Rickets) due to deposition of unmineralized osteoid. Least common is a pectus carinatum malformation following open-heart surgery or in children with poorly controlled bronchial asthma.

Pectus carinatum is generally a solitary, non-syndromic abnormality. However, the condition may be present in association with other syndromes: Turner syndrome, Noonan syndrome, Loeys-Dietz syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Morquio syndrome, trisomy 18, trisomy 21, homocystinuria, osteogenesis imperfecta, multiple lentigines syndrome (LEOPARD syndrome), Sly syndrome (mucopolysaccharidosis type VII), and scoliosis.

In about 25% of cases of pectus carinatum, the patient has a family member with the condition.

People with pectus carinatum usually develop normal hearts and lungs, but the malformation may prevent these from functioning optimally. In moderate to severe cases of pectus carinatum, the chest wall is rigidly held in an outward position. Thus, respirations are inefficient and the individual needs to use the accessory muscles for respiration, rather than normal chest muscles, during strenuous exercise. This negatively affects gas exchange and causes a decrease in stamina. Children with pectus malformations often tire sooner than their peers, due to shortness of breath and fatigue. Commonly concurrent is mild to moderate asthma.

Some children with pectus carinatum also have scoliosis (i.e., curvature of the spine). Some have mitral valve prolapse, a condition in which the heart mitral valve functions abnormally. Connective tissue disorders involving structural abnormalities of the major blood vessels and heart valves are also seen. Although rarely seen, some children have other connective tissue disorders, including arthritis, visual impairment and healing impairment.

Apart from the possible physiologic consequences, pectus malformations can have a significant psychologic impact. Some people, especially those with milder cases, live happily with pectus carinatum. For others, though, the shape of the chest can damage their self-image and confidence, possibly disrupting social connections and causing them to feel uncomfortable throughout adolescence and adulthood. As the child grows older, bodybuilding techniques may be useful for balancing visual impact.

A less common variant of pectus carinatum is "pectus arcuatum" (also called type 2 pectus excavatum, chondromanubrial malformation or Currarino–Silverman syndrome or pouter pigeon malformation), which produces a manubrial and upper sternal protrusion, particularly also at the sternal angle. Pectus arcuatum is often confused with a combination of pectus carinatum and pectus excavatum, but in pectus arcuatum the visual appearance is characterized by a protrusion of the costal cartilages and there is no depression of the sternum.

Antley–Bixler syndrome, also called trapezoidocephaly-synostosis syndrome, is a rare, very severe autosomal recessive congenital disorder characterized by malformations and deformities affecting the majority of the skeleton and other areas of the body.

The following are clear signs of Kyphoscoliosis:

- Abnormal hunch along with a presence of S or C-like shape.

- Uneven lengths of arms and legs

- Presence of associated disorders likes hypertension, neurological disorders

- Abnormal gait

Nager acrofacial dysostosis is a genetic congenital anomaly syndrome. Nager syndrome displays several or all of the following characteristics: underdevelopment of the cheek and jaw area, down-sloping of the opening of the eyes, lack or absence of the lower eyelashes, kidney or stomach reflux, hammer toes, shortened soft palate, lack of development of the internal and external ear, possible cleft palate, underdevelopment or absence of the thumb, hearing loss (see hearing loss with craniofacial syndromes) and shortened forearms, as well as poor movement in the elbow, and may be characterized by accessory tragi. Occasionally, affected individuals develop vertebral anomalies such as scoliosis. The inheritance pattern is said to be autosomal but there are arguments as to whether it is autosomal dominant or autosomal recessive. Most cases tend to be sporadic. Nager syndrome is also linked to five other similar syndromes: Miller syndrome, Treacher Collins, Pierre Robin, Genee-Wiedemann, and Franceschetti-Zwahlen-Klein.

Most of the readily visible signs are associated with the skeletal system. Many individuals with Marfan syndrome grow to above-average height, and some have disproportionately long, slender limbs with thin, weak wrists and long fingers and toes. Besides affecting height and limb proportions, people with Marfan syndrome may have abnormal lateral curvature of the spine (scoliosis), thoracic lordosis, abnormal indentation (pectus excavatum) or protrusion (pectus carinatum) of the sternum, abnormal joint flexibility, a high-arched palate with crowded teeth and an overbite, flat feet, hammer toes, stooped shoulders, and unexplained stretch marks on the skin. It can also cause pain in the joints, bones and muscles. Some people with Marfan have speech disorders resulting from symptomatic high palates and small jaws. Early osteoarthritis may occur. Other signs include limited range of motion in the hips due to the femoral head protruding into abnormally deep hip sockets.