Miller-Dieker occurs in less than one in 100000 people and can occur in all races.

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.

A large British study from 2008 found a median estimated life expectancy of 11.6 years.

Most individuals with this condition do not survive beyond childhood. Individuals with MDS usually die in infancy and therefore do not live to the age where they can reproduce and transmit MDS to their offspring.

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.

A contiguous gene syndrome (CGS), also known as a contiguous gene deletion syndrome is a clinical phenotype caused by a chromosomal abnormality, such as a deletion or duplication that removes several genes lying in close proximity to one another on the chromosome. The combined phenotype of the patient is a combination of what is seen when any individual has disease-causing mutations in any of the individual genes involved in the deletion. While it can be caused by deleted material on a chromosome, it is not, strictly speaking, the same entity as a segmental aneuploidy syndrome. A segmental aneuploidy syndrome is a subtype of CGS that regularly recur, usually due to non-allelic homologous recombination between low copy repeats in the region. Most CGS involve the X chromosome and affect male individuals.

One of the earliest and most famous examples of a CGS involves a male patient with Duchenne muscular dystrophy (DMD), chronic granulomatous disease (CGD), retinitis pigmentosa and intellectual disability. When it was discovered that an X chromosome deletion (specifically Xp21) was the underlying cause of all of these features, researchers were able to use this information to clone the genes responsible for DMD and CGD.

One of those more common CGS involves a deletion on the X chromosome (near Xp21) that encompasses "DMD" (causing Duchenne muscular dystrophy), "NROB1" (causing X-linked adrenal hypoplasia congenita) and "GK" (causing glycerol kinase deficiency). These patients will have all the common features of each individual disease, resulting in a very complex phenotype. Deletions near the distal tip of the p arm of the X chromosome are also a frequent cause of CGS. In addition to the previously described CGS that occur on the X chromosome, two other common syndromes are Langer-Giedion syndrome (caused by deletions of "TRPS1" and "EXT1" on 8q24 and WAGR syndrome (caused by deletions on 11q13 encompassing "PAX6" and "WT1".)

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

It is thought to have an estimated incidence of 1 in 75,000 people.

Potocki–Shaffer syndrome follows an autosomal dominant inheritance pattern, which means a deletion of genetic material from one copy of chromosome 11 is sufficient to cause the disorder. In some cases, an affected person inherits the chromosome with a deleted segment from an affected parent. More commonly, the condition results from a deletion that occurs during the formation of reproductive cells (eggs and sperm) in a parent or in early fetal development. These cases occur in people with no history of the disorder in their family.

Tetra-amelia syndrome has been reported in only a few families worldwide.

According to a 2011 study by Bermejo-Sanchez, amelia – that is, the lacking of one or more limbs – occurs in roughly 1 out of every 71,000 pregnancies.

MORM syndrome is an autosomal recessive congenital disorder This means that the disorder is present from birth and is likely the result of both healthy parents passing on a defective gene, associated with MORM syndrome, to their offspring. The disorder is not dependent on sex of the offspring, both male and female offspring are equally likely to inherit the disorder. The term MORM is used to describe the characteristics associated with the disorder which include mental retardation, truncal obesity, retinal dystrophy, and micropenis". The disorder shares similar characteristics with Bardet-Biedl syndrome and Cohen syndrome, both of which are autosomal recessive genetic disorders. MORM syndrome can be distinguished from the above disorders because symptoms appear at a young age.

The syndrome is caused by a mutation in the INPP5E gene which can be located on chromosome 9 in humans. Further mapping resulted in the identification of a MORM syndrome locus on chromosome 9q34.3 between the genetic markers D9S158 and D9S905.

The varied signs and symptoms of Duane-radial ray syndrome often overlap with features of other disorders.

- For example, acro-renal-ocular syndrome is characterized by Duane anomaly and other eye abnormalities, radial ray malformations, and kidney defects. Both conditions can be caused by mutations in the same gene. Based on these similarities, researchers are investigating whether Duane-radial ray syndrome and acro-renal-ocular syndrome are separate disorders or part of a single syndrome with many possible signs and symptoms.

- The features of Duane-radial ray syndrome also overlap with those of a condition called Holt-Oram syndrome; however, these two disorders are caused by mutations in different genes.

The syndrome is caused by mutations in the RPS6KA3 gene. This gene is located on the short arm of the X chromosome (Xp22.2). The RPS6KA3 gene makes a protein that is involved with signaling within cells. Researchers believe that this protein helps control the activity of other genes and plays an important role in the brain. The protein is involved in cell signaling pathways that are required for learning, the formation of long-term memories, and the survival of nerve cells. The protein RSK2 which is encoded by the RPS6KA3 gene is a kinase which phosphorylates some substrates like CREB and histone H3. RSK2 is involved at the distal end of the Ras/MAPK signaling pathway. Mutations in the RPS6KA3 disturb the function of the protein, but it is unclear how a lack of this protein causes the signs and symptoms of Coffin–Lowry syndrome. At this time more than 120 mutations have been found. Some people with the features of Coffin–Lowry syndrome do not have identified mutations in the RPS6KA3 gene. In these cases, the cause of the condition is unknown.

This condition is inherited in an X-linked dominant pattern. A condition is considered X-linked if the gene that causes the disorder is located on the X chromosome (one of the two sex chromosomes). The inheritance is dominant if one copy of the altered gene is sufficient to cause the condition.

A majority of boys with Coffin–Lowry syndrome have no history of the condition in their families. These cases are caused by new mutations in the RPS6KA3 gene (de novo mutations). A new mutation means that neither parent has the altered gene, but the affected individual could pass it on to his children.

Treatment for the disease itself is nonexistent, but there are options for most of the symptoms. For example, one suffering from hearing loss would be given hearing aids, and those with Hirschsprung’s disorder can be treated with a colostomy.

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.

Coffin–Lowry syndrome is a genetic disorder that is X-linked dominant and which causes severe mental problems sometimes associated with abnormalities of growth, cardiac abnormalities, kyphoscoliosis, as well as auditory and visual abnormalities.

Chromosomal deletion syndromes result from deletion of parts of chromosomes. Depending on the location, size, and whom the deletion is inherited from, there are a few known different variations of chromosome deletions. Chromosomal deletion syndromes typically involve larger deletions that are visible using karyotyping techniques. Smaller deletions result in Microdeletion syndrome, which are detected using fluorescence in situ hybridization (FISH)

Examples of chromosomal deletion syndromes include 5p-Deletion (cri du chat syndrome), 4p-Deletion (Wolf-Hirschhorn syndrome), Prader–Willi syndrome, and Angelman syndrome.

FG syndrome (FGS; also known as Opitz–Kaveggia syndrome) is a rare genetic syndrome caused by one or more recessive genes located on the X chromosome and causing physical anomalies and developmental delays. FG syndrome was named after the first letters of the surnames of the first patients noted with the disease. First reported by Opitz and Kaveggia in 1974, its major clinical features include intellectual disability, hyperactivity, hypotonia (low muscle tone), and a characteristic facial appearance including macrocephaly (an abnormally large head).

Potocki–Shaffer syndrome can be detected through array comparative genomic hybridization (aCGH).

Some symptoms can be managed with drug therapy, surgery and rehabilitation, genetic counselling, and palliative care.

Kabuki syndrome (also previously known as kabuki makeup syndrome, KMS or Niikawa–Kuroki Syndrome), is a pediatric congenital disorder of suspected genetic origin with multiple congenital anomalies and intellectual disabilities. It is quite rare, affecting roughly one in 32,000 births. It was identified and described in 1981 by two Japanese groups, led by the scientists Norio Niikawa and Yoshikazu Kuroki. It is named kabuki syndrome because of the facial resemblance of affected individuals to stage makeup used in kabuki, a Japanese traditional theatrical form.

Myhre syndrome is a rare genetic disorder inherited in an autosomal dominant fashion. It is caused by mutation in SMAD4 gene.

Hurler syndrome has an overall frequency of one per 100,000. The mucopolysaccharidoses as a whole have a frequency of one in every 25,000 births.

The treatments of kabuki syndrome are still being developed due to its genetic nature. The first step to treatment is diagnosis. After diagnosis, the treatment of medical conditions can often be treated by medical intervention. There are also options in psychotherapy for young children with this disorder, as well as the family of the child. Genetic counseling is available as a preventative treatment for kabuki syndrome because it can be inherited and expressed by only having one copy of the mutated gene.

WAGR syndrome is caused by a mutation on chromosome 11 in the 11p13 region. Specifically, several genes in this area are deleted, including the PAX6 ocular development gene and the Wilms' tumour gene (WT1). Abnormalities in WT1 may also cause genitourinary anomalies. Mutations in the PAX6 gene have recently been shown to not only cause ocular abnormalities, but also problems in the brain and pancreas.

The gene for brain-derived neurotrophic factor (BDNF), located on 11p14.1, has been proposed as a candidate gene for the obesity and excessive eating in a subset of WAGR patients. This strengthens the case for a role for BDNF in energy balance.

Potocki–Lupski syndrome (PTLS), also known as dup(17)p11.2p11.2 syndrome, trisomy 17p11.2 or duplication 17p11.2 syndrome, is a contiguous gene syndrome involving the microduplication of band 11.2 on the short arm of human chromosome 17 (17p11.2). The duplication was first described as a case study in 1996. In 2000, the first study of the disease was released, and in 2007, enough patients had been gathered to complete a comprehensive study and give it a detailed clinical description. PTLS is named for two researchers involved in the latter phases, Drs. Lorraine Potocki and James R. Lupski of Baylor College of Medicine.

PTLS was the first predicted of a homologous recombination (microdeletion or microduplication) where both reciprocal recombinations result in a contiguous gene syndrome. Its reciprocal disease is Smith–Magenis syndrome (SMS), in which the chromosome portion duplicated in PTLS is deleted altogether.

Potocki–Lupski syndrome is considered a rare disease, predicted to appear in at least 1 in 20,000 humans.

Symptoms of the syndrome include intellectual disability, autism, and other disorders unrelated to the listed symptoms.