Although no cause has been officially confirmed, researchers speculate the disease might result from a genetic mutation that sporadically occurs for unknown reasons.

In utero exposure to cocaine and other street drugs can lead to septo-optic dysplasia.

Craniofrontonasal dysplasia is a very rare genetic condition. As such there is little information and no consensus in the published literature regarding the epidemiological statistics.

The incidence values that were reported ranged from 1:100,000 to 1:120,000.

The outlook for individuals with EDS depends on the type of EDS they have. Symptoms vary in severity, even within one sub-type, and the frequency of complications changes individually. Some people have negligible symptoms while others are severely restricted in their daily life. Extreme joint instability, chronic musculoskeletal pain, degenerative joint disease, frequent injuries, and spinal deformities may limit mobility. Severe spinal deformities may affect breathing. In the case of extreme joint instability, dislocations may result from simple tasks such as rolling over in bed or turning a doorknob. Secondary conditions such as autonomic dysfunction or cardiovascular problems, occurring in any type, can affect prognosis and quality of life. Severe mobility-related disability is seen more often in Hypermobility-type than in Classical-type or Vascular-type.

Although all types are potentially life-threatening, the majority of individuals will have a normal lifespan. However, those with blood vessel fragility have a high risk of fatal complications. Arterial rupture is the most common cause of sudden death in EDS. Spontaneous arterial rupture most often occurs in the second or third decade, but can occur at any time. The median life-expectancy in the population with Vascular EDS is 48 years.

By 1990, 65 patients had been reported in the literature, with no sex or ethnic preference notable. Some individuals present with minimal malformation; rarely patients have died during infancy as a result of severe central nervous system involvement or respiratory complications. Several syndromes are related to the Freeman–Sheldon syndrome spectrum, but more information is required before undertaking such nosological delineation.

Though the children affected with CLSD will have problems throughout life, the treatment for this disease thus far is symptomatic. However, prognosis is good; at the time of the most recently published articles, identified children were still alive at over 4 years of age.

Mutant proteins still maintain some residual activity, allowing for the release of some collagen, but still form an extremely distended endoplasmic reticulum.

There are little data on prognosis. Rarely, some patients have died in infancy from respiratory failure; otherwise, life expectancy is considered to be normal.

Ischiopatellar dysplasia is often considered a familial condition. Ischiopatellar dysplasia has been identified on region 5.6 cM on chromosome 17q22. Mutations in the TBX4 (T-box protein 4) gene have been found to cause ischiopatellar dysplasia due to the essential role TBX4 plays in lower limb development since TBX4 is a transcription factor.

Cranio–lenticulo–sutural dysplasia (CLSD, or Boyadjiev-Jabs syndrome) is a neonatal/infancy disease caused by a disorder in the 14th chromosome. It is an autosomal recessive disorder, meaning that both recessive genes must be inherited from each parent in order for the disease to manifest itself. The disease causes a significant dilation of the endoplasmic reticulum in fibroblasts of the host with CLSD. Due to the distension of the endoplasmic reticulum, export of proteins (such as collagen) from the cell is disrupted.

The production of SEC23A protein is involved in the pathway of exporting collagen (the COPII pathway), but a missense mutation causes and underproduction of SEC23A which inhibits the pathway, affecting collagen secretion. This decrease in collagen secretion can lead to the bone defects that are also characteristic of the disease, such as skeletal dysplasia and under-ossification. Decreased collagen in CLSD-affected individuals contributes to improper bone formation, because collagen is a major protein in the extracellular matrix and contributes to its proper mineralization in bones. It has also been hypothesized that there are other defects in the genetic code besides SEC23A that contribute to the disorder.

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.

Rare familial recurrence has been reported, suggesting at least one genetic form (HESX1). In addition to HESX1, mutations in OTX2, SOX2 and PAX6 have been implicated in de Morsier syndrome, but in most cases SOD is a sporadic birth defect of unknown cause and does not recur with subsequent pregnancies.

Parents of a proband

- The parents of an affected individual are obligate heterozygotes and therefore carry one mutant allele.

- Heterozygotes (carriers) are asymptomatic.

Sibs of a proband

- At conception, each sibling of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.

- Once an at-risk sibling is known to be unaffected, the risk of his/her being a carrier is 2/3.

- Heterozygotes (carriers) are asymptomatic.

Offspring of a proband

- Offspring of a proband are obligate heterozygotes and will therefore carry one mutant allele.

- In populations with a high rate of consanguinity, the offspring of a person with GPR56-related BFPP and a reproductive partner who is a carrier of GPR56-related BFPP have a 50% chance of inheriting two GPR56 disease-causing alleles and having BFPP and a 50% chance of being carriers.

Other family members of a proband.

- Each sibling of the proband's parents is at a 50% risk of being a carrier

Several studies have reported that life expectancy appears to be normal for people with CCD.

While only a few adults have been reported with 2q37 microdeletion syndrome, it is predicted that this number will rise as various research studies continue to demonstrate that most with the disorder do not have a shortened life span.

Ehlers–Danlos syndrome is an inherited disorder estimated to occur in about 1 in 5,000 births worldwide. Initially, prevalence estimates ranged from 1 in 250,000 to 1 in 500,000 people, but these estimates were soon found to be vastly inaccurate as the disorder received further study and medical professionals became more adept at accurately diagnosing EDS. In fact, many experts now believe that Ehlers–Danlos syndrome may be far more common than the currently accepted estimate due to the wide range of severities with which the disorder presents.

The prevalence of the 13 types differs dramatically. The most commonly occurring is the Hypermobility type, followed by the Classical type. The other types of Ehlers–Danlos syndrome are very rare. For example, fewer than ten infants and children with the dermatosparaxis type have been described worldwide. Some types of Ehlers–Danlos are more common in Ashkenazi Jews. For example, the chance of being a carrier for type-VIIc Ehlers–Danlos is 1 in 248 in Ashkenazi Jews, whereas the prevalence of this mutation in the general population is 1 in 2,000.

The condition develops in the fetus at approximately 4 weeks gestational age, when some form of vascular problem such as blood clotting leads to insufficient blood supply to the face. This can be caused by physical trauma, though there is some evidence of it being hereditary . This restricts the developmental ability of that area of the face. Currently there are no definitive reasons for the development of the condition.

Ischiopatellar dysplasia is a rare autosomal dominant disorder characterized by a hypoplasia of the patellae as well as other bone anomalies, especially concerning the pelvis and feet.

Raine syndrome (RNS), also called osteosclerotic bone dysplasia, is a rare autosomal recessive congenital disorder characterized by craniofacial anomalies including microcephaly, noticeably low set ears, osteosclerosis, a cleft palate, gum hyperplasia, a hypoplastic nose, and eye proptosis. It is considered to be a lethal disease, and usually leads to death within a few hours of birth. However, a recent report describes two studies in which children with Raine Syndrome have lived to 8 and 11 years old, so it is currently proposed that there is a milder expression that the phenotype can take (Simpson 2009).

It was first characterized in 1989 in a report that was published on an infant that had been born with an unknown syndrome, that later came to be called Raine Syndrome.

The current research describes Raine Syndrome as a neonatal osteosclerotic bone dysplasia, indicated by its osteosclerotic symptoms that are seen in those suffering from the disease. It has been found that a mutation in the gene FAM20C is the cause of the Raine Syndrome phenotype. This microdeletion mutation leads to an unusual chromosome 7 arrangement. The milder phenotypes of Raine Syndrome, such as those described in Simpson’s 2007 report, suggest that Raine Syndrome resulting from missense mutations may not be as lethal as the other described mutations (OMIM). This is supported by findings from Fradin et al. (2011), who reported on children with missense mutations to FAM20C and lived to ages 1 and 4 years, relatively much longer than the life spans of the previously reported children. Simpson et al.’s (2007) report states that to date, effected individuals have had chromosome 7 uniparental isodisomy and a 7p telomeric microdeletion. They had abnormal chromosome 7 arrangements, with microdeletions of their D7S2477 and D7S1484 markers (Simpson 2007).

Raine Syndrome appears to be an autosomal recessive disease. There are reports of recurrence in children born of the same parents, and an increased occurrence in children of closely related, genetically similar parents. Individuals with Raine Syndrome were either homozygous or compound heterozygous for the mutation of FAM20C. Also observed have been nonsynonomous mutation and splice-site changes (Simpson et al. 2007).

FAM20C, located on chromosome 7p22.3, is an important molecule in bone development. Studies in mice have demonstrated its importance in the mineralization of bones in teeth in early development (OMIM, Simpson et al. 2007, Wang et al. 2010). FAM20C stands for “family with sequence similarity 20, member C.” It is also commonly referred to as DMP-4. It is a Golgi-enriched fraction casein kinase and an extracellular serine/threonine protein kinase. It is 107,743 bases long, with 10 exons and 584 amino acids (Weizmann Institute of Science).

Individuals affected by certain ED syndromes cannot perspire. Their sweat glands may function abnormally or may not have developed at all because of inactive proteins in the sweat glands. Without normal sweat production, the body cannot regulate temperature properly. Therefore, overheating is a common problem, especially during hot weather. Access to cool environments is important.

Till date about 18 cases of Spondylocostal dysostosis have been reported in literature.

It is usually autosomal dominant, but in some cases the cause is not known. It occurs due to haploinsufficiency caused by mutations in the CBFA1 gene (also called Runx2), located on the short arm of chromosome 6, which encodes transcription factor required for osteoblast differentiation. It results in delayed ossification of midline structures of the body, particularly membranous bone.

A new article reports that the CCD cause is thought to be due to a CBFA1 (core binding factor activity 1) gene defect on the short arm of chromosome 6p21 . CBFA1 is vital for differentiation of stem cells into osteoblasts, so any defect in this gene will cause defects in membranous and endochondral bone formation.

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.

The aneuploidy is thought to be caused by problems occurring during meiosis, either in the mother or in both the mother and father. Successive nondisjunctions have been observed in the mother of at least one patient.

The features of the syndrome likely arise due to failure of X-inactivation and the presence of multiple X chromosomes from the same parent causing problems with parental imprinting. In theory, X-inactivation should occur and leave only one X chromosome active in each cell. However, failure of this process has been observed in one individual studied. The reason for this is thought to be the presence of an unusually large, and imbalanced, number of X chromosomes interfering with the process.

Several studies have examined salivary flow rate in individuals and found parotid and submandibular salivary flow ranging from 5 to 15 times lower than average. This is consistent with the salivary glands being of ectodermal origin, although some findings have suggested that there is also mesodermal input.

Sensenbrenner syndrome (OMIM #218330) is a rare (less than 20 cases reported by 2010) multisystem disease first described in 1975. It is inherited in an autosomal recessive fashion, and a number of genes appear to be responsible. Three genes responsible have been identified: intraflagellar transport (IFT)122 (WDR10), IFT43 — a subunit of the IFT complex A machinery of primary cilia, and WDR35 (IFT121: TULP4)

It is also known as Sensenbrenner–Dorst–Owens syndrome, Levin Syndrome I and cranioectodermal dysplasia (CED)