Overall, the estimated prevalence of Stickler syndrome is about 1 in 10,000 people. Stickler syndrome affects 1 in 7,500 to 9,000 newborns.

Roberts syndrome is an extremely rare condition that only affects about 150 reported individuals. Although there have been only about 150 reported cases, the affected group is quite diverse and spread worldwide. Parental consanguinity (parents are closely related) is common with this genetic disorder. The frequency of Roberts syndrome carriers is unknown.

Many professionals that are likely to be involved in the treatment of those with Stickler's syndrome, include anesthesiologists, oral and maxillofacial surgeons; craniofacial surgeons; ear, nose, and throat specialists, ophthalmologists, optometrists, audiologists, speech pathologists, physical therapists and rheumatologists.

Muenke syndrome is caused by a specific gene mutation in the FGFR3 gene. The mutation arises randomly; there is no full understanding for what causes this mutation. This mutation causes the FGFR3 protein to be overly active; it interferes with normal bone growth, and allows skull bones to fuse prematurely. There is no connection between anything mother did (or did not do) to activate the syndrome. If neither of the parents have Muenke syndrome, chances of having another child with the syndrome are minimal.

This condition is inherited in an autosomal dominant pattern. This means if a parent has Muenke syndrome, every newborn has a 50% chance of inheriting the syndrome.

Stickler syndrome and Marshall syndrome have an autosomal dominant pattern of inheritance. However, there is a great deal of variation within and among families with regard to gene expression. Some may be more severely affected and others may be very mildly affected. Often these syndromes are not recognized in a family until a baby is born with Pierre Robin syndrome or some members have detached retinas or cataracts at a young age.

Both syndromes where correlated with mutations in the COL11A1 gene.

While not always pathological, it can present as a birth defect in multiple syndromes including:

- Catel–Manzke syndrome

- Bloom syndrome

- Coffin–Lowry syndrome

- congenital rubella

- Cri du chat syndrome

- DiGeorge's syndrome

- Ehlers-Danlos syndrome

- fetal alcohol syndrome

- Hallermann-Streiff syndrome

- Hemifacial microsomia (as part of Goldenhar syndrome)

- Juvenile idiopathic arthritis

- Marfan syndrome

- Noonan syndrome

- Pierre Robin syndrome

- Prader–Willi syndrome

- Progeria

- Russell-Silver syndrome

- Seckel syndrome

- Smith-Lemli-Opitz syndrome

- Treacher Collins syndrome

- Trisomy 13 (Patau syndrome)

- Trisomy 18 (Edwards syndrome)

- Wolf–Hirschhorn syndrome

- X0 syndrome (Turner syndrome)

It is likely that this syndrome is inherited in an autosomal dominant fashion, however there may be a recessive form with hypotonia and developmental delay.

At this time, there are no other phenotypes (observable expressions of a gene) that have been discovered for mutations in the ESCO2 gene.

Marshall syndrome is a genetic disorder of the connective tissue which can cause hearing loss. The three most common areas to be affected are the eyes which are uncommonly large, joints and the mouth and facial structures. Marshall syndrome and Stickler syndrome closely resemble each other; in fact they are so similar, some say they are the same.

3C syndrome is very rare, occurring in less than 1 birth per million. Because of consanguinity due to a founder effect, it is much more common in a remote First Nations village in Manitoba, where 1 in 9 people carries the recessive gene.

Muenke syndrome is inherited in an autosomal dominant pattern. In some cases, an affected person inherits the mutation from one affected parent. If a patient is shown to have Muenke, they have a 50/50 chance of passing it on to their children. Not all cases of Muenke however is obvious. Other cases may result from new mutations in the gene. These cases occur in people with no history of the disorder in their family.

A single mutation in the FGFR3 gene cause this syndrome. The FGFR3 gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. This mutation causes the FGFR3 protein to be overly active, which interferes with normal bone growth and allows the bones of the skull to fuse before they should.

As stated by researchers at the University of Washington, Muenke syndrome is inherited in an autosomal dominant manner with incomplete penetrance and variable expressivity.” Prenatal diagnosis for pregnancies at increased risk is possible if the defining mutation has been identified in the family (Agochukwu et.al. 2006). According to the article "Craniosynostosis: Molecular Genetics," penetrance is higher in females (87%) than in males (76%). Muenke syndrome is estimated to account for 25%-30% of all genetic causes of craniosynostosis according to the Journal of Anatomy.

Respiratory complications are often cause of death in early infancy.

If the Hirschsprung's disease is treated in time, ABCD sufferers live otherwise healthy lives. If it is not found soon enough, death often occurs in infancy. For those suffering hearing loss, it is generally regressive and the damage to hearing increases over time. Digestive problems from the colostomy and reattachment may exist, but most cases can be treated with laxatives. The only other debilitating symptom is hearing loss, which is usually degenerative and can only be treated with surgery or hearing aids.

Some people may have some mental slowness, but children with this condition often have good social skills. Some males may have problems with fertility.

The original report was of a family in Cardiff, United Kingdom. There are subsequent reports of patients from the USA, France, Australia, UAE, India and from Cuba.

The first gene that could cause the syndrome is described recently and is called NF1X (chromosome 19: 19p13.1).

It can be detected by the naked eye as well as dental or skull X-Ray testing.

Low-set ears are ears with depressed positioning of the pinna two or more standard deviations below the population average.

It can be associated with conditions such as:

- Down's syndrome

- Turner Syndrome

- Noonan syndrome

- Patau syndrome

- DiGeorge syndrome

- Cri du chat syndrome

- Edwards syndrome

- Fragile X syndrome

It is usually bilateral, but can be unilateral in Goldenhar syndrome.

The specific cause of camptodactyly remains unknown, but there are a few deficiencies that lead to the condition. A deficient lumbrical muscle controlling the flexion of the fingers, and abnormalities of the flexor and extensor tendons.

A number of congenital syndromes may also cause camptodactyly:

- Jacobsen syndrome

- Beals Syndrome

- Blau syndrome

- Freeman-Sheldon syndrome

- Cerebrohepatorenal syndrome

- Weaver syndrome

- Christian syndrome 1

- Gordon Syndrome

- Jacobs arthropathy-camptodactyly syndrome

- Lenz microphthalmia syndrome

- Marshall-Smith-Weaver syndrome

- Oculo-dento-digital syndrome

- Tel Hashomer camptodactyly syndrome

- Toriello-Carey syndrome

- Stuve-Wiedemann syndrome

- Loeys-Dietz syndrome

- Fryns syndrome

- Marfan's syndrome

- Carnio-carpo-tarsal dysthropy

The prognosis varies widely from case to case, depending on the severity of the symptoms. However, almost all people reported with Aicardi syndrome to date have experienced developmental delay of a significant degree, typically resulting in mild to moderate to profound intellectual disability. The age range of the individuals reported with Aicardi syndrome is from birth to the mid 40s.

There is no cure for this syndrome.

The incidence of Fraser syndrome is 0.043 per 10,000 live born infants and 1.1 in 10,000 stillbirths, making it a rare syndrome.

Worldwide prevalence of Aicardi Syndrome is estimated at several thousand, with approximately 900 cases reported in the United States.

Malpuech facial clefting syndrome, also called Malpuech syndrome or Gypsy type facial clefting syndrome, is a rare congenital syndrome. It is characterized by facial clefting (any type of cleft in the bones and tissues of the face, including a cleft lip and palate), a appendage (a "human tail"), growth deficiency, intellectual and developmental disability, and abnormalities of the renal system (kidneys) and the male genitalia. Abnormalities of the heart, and other skeletal malformations may also be present. The syndrome was initially described by Guilliaume Malpuech and associates in 1983. It is thought to be genetically related to Juberg-Hayward syndrome. Malpuech syndrome has also been considered as part of a spectrum of congenital genetic disorders associated with similar facial, urogenital and skeletal anomalies. Termed "3MC syndrome", this proposed spectrum includes Malpuech, Michels and Mingarelli-Carnevale (OSA) syndromes. Mutations in the "COLLEC11" and "MASP1" genes are believed to be a cause of these syndromes. The incidence of Malpuech syndrome is unknown. The pattern of inheritance is autosomal recessive, which means a defective (mutated) gene associated with the syndrome is located on an autosome, and the syndrome occurs when two copies of this defective gene are inherited.

Usher syndrome, also known as Hallgren syndrome, Usher-Hallgren syndrome, retinitis pigmentosa-dysacusis syndrome, or dystrophia retinae dysacusis syndrome, is an extremely rare genetic disorder caused by a mutation in any one of at least 11 genes resulting in a combination of hearing loss and visual impairment. It is a leading cause of deafblindness and is at present incurable.

Usher syndrome is classed into three subtypes according to onset and severity of symptoms. All three subtypes are caused by mutations in genes involved in the function of the inner ear and retina. These mutations are inherited in an autosomal recessive pattern.

Prognoses for 3C syndrome vary widely based on the specific constellation of symptoms seen in an individual. Typically, the gravity of the prognosis correlates with the severity of the cardiac abnormalities. For children with less severe cardiac abnormalities, the developmental prognosis depends on the cerebellar abnormalities that are present. Severe cerebellar hypoplasia is associated with growth and speech delays, as well as hypotonia and general growth deficiencies.