PWS affects approximately 1 in 10,000 to 1 in 25,000 newborns. There are more than 400,000 people who live with PWS around the world.

Treatment with isotretinoin may induce substantial resolution of skin lesions, but the risk of secondary infection remains.

GMS syndrome is a syndrome characterised by goniodysgenesis, intellectual disability, and short stature.

Lujan–Fryns syndrome is a rare X-linked dominant syndrome, and is therefore more common in males than females. Its prevalence within the general population has not yet been determined.

The estimated prevalence of Jacobsen syndrome is believed to be approximately 1 out of every 100,000 births. For reasons unknown females are twice as likely to have Jacobsen Syndrome than males. No preference for any race or ethnicity has been reported so far.

PWS is commonly associated with development of strabismus. In one study, over 50% of patients had strabismus, mainly esotropia.

As its name indicates, a person with the syndrome has one Y chromosome and four X chromosomes on the 23rd pair, thus having 49 chromosomes rather than the normal 46. As with most categories of aneuploidy disorders, 49,XXXXY syndrome is often accompanied by intellectual disability. It can be considered a form of 47, XXY Klinefelter syndrome, or a variant of it.

It is genetic but not hereditary. This means that while the genes of the parents cause the syndrome, there is a small chance of more than one child having the syndrome. The probability of inheriting the disease is about 1%.

The individuals with this syndrome are males, but 49, XXXXX also exists with similar characteristics.

The syndrome primarily affects young males. Preliminary studies suggest that prevalence may be 1.8 per 10,000 live male births. 50% of those affected do not live beyond 25 years of age, with deaths attributed to the impaired immune function.

Since tetrasomy 9p is not usually inherited, the risk of a couple having a second child with the disorder is minimal. While patients often do not survive to reproductive age, those who do may or may not be fertile. The risk of a patient's child inheriting the disorder is largely dependent on the details of the individual's case.

Jacobsen Syndrome is caused due to deletion of genetic material from the long arm of chromosome 11. The size of deletion may vary across patients but the deletion always occurs at the end terminal of the q arm of chromosome 11. There are three ways in which the deletion could occur:

de novo deletion- this is a random event that occurred during the formation of the sperm or the egg or during the cell division in the embryonic stage, where genes from chromosome 11 get deleted.

Imbalanced translocation- in this case a parent with balanced translocation or other types of chromosomal rearrangement can pass on these genes to their children which further results in an imbalanced translocation. In this case the affected children have deletions on chromosome 11 as well as some extra genetic material from another chromosome.

Ring chromosome 11- in this case genetic material from both long and short arm of the chromosome get deleted and the remaining part joins together and forms a ring like structure. Here the affected person would have symptoms associated with both 11q and 11p deletion.

Sotos syndrome is not a life-threatening disorder and patients may have a normal life expectancy. Developmental delays may improve in the school-age years; however, coordination problems may persist into adulthood, along with any learning disabilities and/or other physical or mental issues.

There is no specific treatment for micro syndrome, but there are ways to help the disorders, and illnesses that come with it. Many individuals with Micro Syndrome need permanent assistance from their disorders and inabilities to move and support themselves. Seizures are not uncommon and patients should get therapy to help control them, and many patients also require wheelchairs to move, so an assistant would be needed at all times.

Those with micro syndrome are born appearing normal. At the age of one, mental and physical delays become apparent, along with some limb spasms. By the age of eight micro syndrome has already set in, and the patient will have joint contractures, Ocular Atrophy will become noticeable, the patient will most likely lose ability to walk, speak, and sometimes move at all.

Affected individuals have a somewhat shortened lifespan. The maximum described lifespan is 67 years. Adults with 13q deletion syndrome often need support services to maintain their activities of daily living, including adult day care services or housing services.

The rare cases that have been examined are often within families, or the people that have cases of micro syndrome have a mutation in their genes.

It can be associated with "RAB3GAP".

The true prevalence of PMS has not been determined. More than 1200 people have been identified worldwide according the Phelan-McDermid Syndrome Foundation. However, it is believed to be underdiagnosed due to inadequate genetic testing and lack of specific clinical features. It is known to occur with equal frequency in males and females. Studies using chromosomal microarray for diagnosis indicate that at least 0.5% of cases of ASD can be explained by mutations or deletions in the "SHANK3" gene. In addition when ASD is associated with ID, "SHANK3" mutations or deletions have been found in up to 2% of individuals.

Cri du chat syndrome, also known as chromosome 5p deletion syndrome, 5p− syndrome (pronounced "Five P Minus") or Lejeune’s syndrome, is a rare genetic disorder due to chromosome deletion on chromosome 5. Its name is a French term ("cat-cry" or "call of the cat") referring to the characteristic cat-like cry of affected children. It was first described by Jérôme Lejeune in 1963. The condition affects an estimated 1 in 50,000 live births across all ethnicities and is more common in females by a 4:3 ratio.

With appropriate treatment and management, patients with Weaver syndrome appear to do well, both physically and intellectually, throughout their life and have a normal lifespan. Their adult height is normal as well.

Wolf–Hirschhorn syndrome is a microdeletion syndrome caused by a deletion within HSA band 4p16.3 of the short arm of chromosome 4, particularly in the region of and . About 87% of cases represent a "de novo" deletion, while about 13% are inherited from a parent with a chromosome translocation. In the cases of familial translocation, there is a 2 to 1 excess of maternal transmission. Of the "de novo" cases, 80% are paternally derived. Severity of symptoms and expressed phenotype differ based on the amount of genetic material deleted. The critical region for determining the phenotype is at 4p16.3 and can often be detected through genetic testing and fluorescence in situ hybridization (FISH). Genetic testing and genetic counseling is offered to affected families.

Pallister-Killian does not appear to be hereditary. Some research has suggested that the presence of the extra chromosome may be linked to premeiotic mitotic errors, both maternally and paternally. Several theories regarding the mechanism of this formation have been introduced.

Weaver syndrome and Sotos syndrome are often mistaken for one another due to their significant phenotypic overlap and similarities. Clinical features shared by both syndromes include overgrowth in early development, advanced bone age, developmental delay, and prominent macrocephaly. Mutations in the NSD1 gene may also be another cause for confusion. The NSD1 gene provides instructions for making a protein that is involved in normal growth and development. Deletions and mutations in the NSD1 gene is a common cause for patients with Sotos syndrome and in some cases for Weaver syndrome as well.

Features distinguishing Weaver syndrome from Sotos syndrome include broad forehead and face, ocular hypertelorism, prominent wide philtrum, micrognathia, deep-set nails, retrognathia with a prominent chin crease, increased prenatal growth, and a carpal bone age that is greatly advanced compared to metacarpal and phalangeal bone age.

The prevalence rate has been estimated to be less than 1/1,000,000 worldwide. However, it is much more common in the French-Canadian population of the Saguenay and Lac-St-Jean regions of Quebec, Canada, where it has a frequency of about 1 in 2100 in live births, and a carrier rate of 1 in 23.

Distal trisomy 10 is a rare chromosomal disorder that causes several physical defects and intellectual disability.

Humans, like all sexually reproducing species, have somatic cells that are in diploid [2N] state, meaning that N represent the number of chromosomes, and 2 the number of their copies. In humans, there are 23 chromosomes, but there are two sets of them, one from mother and one from father, totaling in 46, that are arranged according to their size, function and genes they carry. Each cell is supposed to have two of each, but sometimes due to mutations or malfunctions during cell division, mistakes are made that cause serious health problems. One such error is the cause of Distal trisomy 10q disorder.

Each chromosome has two arms, labeled p (for petite, or short) and q (for long). If both arms are equal in length, the chromosome is said to be metacentric. If arms' lengths are unequal, chromosome is said to be submetacentric, and if p arm is so short that is hard to observe, but still present, then the chromosome is acrocentric. In Distal Trisomy 10q disorder, end or distal portion of the q (long) arm of the chromosome number 10 appears to be present three times, rather than two times as it is supposed to be. This extra arm results in chromosome 10 trisomy, meaning that three arms are present. Depending on the length of the aberrant arm, the severity can vary from case to case. Often the source of this chromosomal error is a translocation in one of the parents. Sometimes it occurs spontaneously, in which case it is termed "de novo".

This syndrome has a large range of outcomes depending on how much chromosomal material is involved. Outcomes include: very slow postnatal growth, hypotonia, lack of coordination skills and mild to severe cases of intellectual disability, digestive issues, and heart and kidney problems. Individuals with this disorder can also be distinguished by their facial features. Number of support groups do exist in the United States, where affected families can meet and discuss problems they encounter, possible treatments and can find emotional support.

Though the outcome for individuals with either form of the tetrasomy is highly variable, mosaic individuals consistently experience a more favourable outcome than those with the non-mosaic form. Some affected infants die shortly after birth, particularly those with the non-mosaic tetrasomy. Many patients do not survive to reproductive age, while others are able to function relatively normally in a school or workplace setting. Early diagnosis and intervention has been shown to have a strong positive influence on the prognosis.

This disorder affects all demographics equally. The two families that were studied are of European ancestry. Wilson–Turner syndrome is considered to be a rare disease because it affects one individual out of one million.

Emanuel Syndrome can be diagnosed with a karyotype, with FISH, or with a chromosomal microarray analysis. .