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

Currently, research is focusing on identifying the role of the genes on 18p in causing the signs and symptoms associated with deletions of 18p. This will ultimately enable predictive genotyping.

TGIF-Mutations and deletions of this gene have been associated with holoprosencephaly. Penetrance is incomplete, meaning that a deletion of one copy of this gene is not in and of itself sufficient to cause holoprosencephaly. Ten to fifteen percent of people with 18p- have holoprosencephaly, suggesting that other genetic and environmental facts play a role in the etiology of holoprosencephaly in these individuals.

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.

Exposure of spermatozoa to lifestyle, environmental and/or occupational hazards may increase the risk of aneuploidy. Cigarette smoke is a known aneugen (aneuploidy inducing agent). It is associated with increases in aneuploidy ranging from 1.5 to 3.0-fold. Other studies indicate factors such as alcohol consumption, occupational exposure to benzene, and exposure to the insecticides fenvalerate and carbaryl also increase aneuploidy.

Trisomy 8 mosaicism affects wide areas of chromosome 8 containing many genes, and can thus be associated with a range of symptoms.

- Mosaic trisomy 8 has been reported in rare cases of Rothmund-Thomson syndrome, a genetic disorder associated with the DNA helicase RECQL4 on chromosome 8q24.3. The syndrome is "characterized by skin atrophy, telangiectasia, hyper- and hypopigmentation, congenital skeletal abnormalities, short stature, premature aging, and increased risk of malignant disease".

- Some individuals trisomic for chromosome 8 were deficient in production of coagulation factor VII due to a factor 7 regulation gene (F7R) mapped to 8p23.3-p23.1.

- Trisomy and other rearrangements of chromosome 8 have also been found in tricho–rhino–phalangeal syndrome.

- Small regions of chromosome 8 trisomy and monosomy are also created by recombinant chromosome 8 syndrome (San Luis Valley syndrome), causing anomalies associated with tetralogy of Fallot, which results from recombination between a typical chromosome 8 and one carrying a parental paracentric inversion.

- Trisomy is also found in some cases of chronic myeloid leukaemia, potentially as a result of karyotypic instability caused by the fusion gene.

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.

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The minimal deletion causing this syndrome has been defined as a 3 megabase region that contains the genes GPR35, GPC1 and STK25.

Almost all deletions are found to be terminal deletions at the end of chromosome 2. There is a high frequency of "de novo" deletions, but multiple cases within a single family are also observed. Equal proportions of maternally and paternally derived rearrangements were seen in Aldred's series. No common breakpoints for the deletion were identified indicating that the 2q37 rearrangement is unlikely to be mediated by non-homologous recombination and low-copy repeats. In a study of 20 patients, no clear relationship was found between clinical features and the size or position of the monosomic region.

2q37 monosomy is a rare genetic disorder caused by a deletion of a segment at the end of chromosome 2.

The incidence rate of ATR-16 syndrome is not easy to estimate and it is thought to be underdiagnosed. Scientists have described more than 20 cases as of 2013.

Human trisomies compatible with live birth, other than Down syndrome (trisomy 21), are Edwards syndrome (trisomy 18) and Patau syndrome (trisomy 13). Complete trisomies of other chromosomes are usually not viable and represent a relatively frequent cause of miscarriage. Only in rare cases of a mosaicism, the presence of a normal cell line, in addition to the trisomic cell line, may support the development of a viable trisomy of the other chromosomes.

ATR-16 syndrome is caused by a deletion of part of chromosome 16, from p13.3 (a band on the short end of the chromosome) to the end of the chromosome. These can either be due to a balanced translocation or a de novo deletion. The genes affected include hemoglobin, alpha 1 (HBA1) and hemoglobin, alpha 2 (HBA2).

Trisomy 8, also known as Warkany syndrome 2, is a human chromosomal disorder caused by having three copies (trisomy) of chromosome 8. It can appear with or without mosaicism.

Partial monosomy of chromosome 13q is a monosomy that results from the loss of all or part of the long arm of chromosome 13 in human beings. It is a rare genetic disorder which results in severe congenital abnormalities which are frequently fatal at an early age. Up until 2003, more than 125 cases had been documented in medical literature.

Mosaic trisomy 16, a rare chromosomal disorder, is compatible with life, therefore a baby can be born alive. This happens when only some of the cells in the body contain the extra copy of chromosome 16. Some of the consequences include slow growth before birth.

Most affected people have a stable clinical course but are often transfusion dependent.

Monosomy 9p (also known as Alfi's Syndrome or simply 9P-) is a rare chromosomal disorder in which there is deletion (monosomy) of a portion of chromosome 9. Symptoms include microgenitalia, mental retardation with microcephaly and dysmorphic features.

The location has recently been narrowed to 9p22.2-p23.

Various clinical features have been associated with this disease including trigonocephaly, flattened occiput, prominent forehead, broad flat nasal bridge, anteverted nares, malformed external ears, hypertelorism, and hypertonia.

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.

During prenatal diagnosis the levels of trisomy in fetal-placental tissues can be analyzed. These levels can be predictors of outcomes in mosaic trisomy 16 pregnancies. In a study of prenatal diagnosis cases, there were 66% live births with an average 35.7 weeks gestational age. About 45% of them had malformations. The most common malformations were CSD, ASD, and hypospadias. However, trisomy 16 does not always result in anatomical abnormalities.

Symptoms vary from case to case, and may correlate to how much of the chromosome is missing. Symptoms that are frequently observed with the condition include:

- Low birth weight

- Malformations of the head

- Eye abnormalities

- Defects of the hands and feet, polydactyly

- Reproductive abnormalities (males)

- Psychological and motor retardation

1p36 deletion syndrome (also known as monosomy 1p36) is a congenital genetic disorder characterized by moderate to severe intellectual disability, delayed growth, hypotonia, seizures, limited speech ability, malformations, hearing and vision impairment, and distinct facial features. The symptoms may vary, depending on the exact location of the chromosomal deletion.

The condition is caused by a genetic deletion (loss of a segment of DNA) on the outermost band on the short arm (p) of chromosome 1. It is one of the most common deletion syndromes. It is estimated that the syndrome occurs in one in every 5,000 to 10,000 births. Knowledge of the disorder has increased a great deal over the last decade, mainly because more patients have been accurately diagnosed and described in international medical literature.

Monosomy is a form of aneuploidy with the presence of only one chromosome (instead of the typical two in humans) from a pair, which affects chromosome 14. Fetuses with monosomy 14 are not viable. Only mosaic cases exist and these usually present with severe symptoms such as intellectual disability, ocular colobomata, microcephaly, and seizures.

The 5q-syndrome is characterized by macrocytic anemia, often a moderate thrombocytosis, erythroblastopenia, megakaryocyte hyperplasia with nuclear hypolobation, and an isolated interstitial deletion of chromosome 5. The 5q- syndrome is found predominantly in females of advanced age.

Therapy can help developmental delays, as well as physiotherapy for the low muscle tone. Exercise and healthy eating can reduce weight gain. Treatments are available for seizures, eczema, asthma, infections, and certain bodily ailments.

Cri du chat syndrome is due to a partial deletion of the short arm of chromosome number 5, also called "5p monosomy" or "partial monosomy." Approximately 90% of cases result from a sporadic, or randomly occurring, "de novo" deletion. The remaining 10-15% are due to unequal segregation of a parental balanced translocation where the 5p monosomy is often accompanied by a trisomic portion of the genome. These individuals may have more severe disease than those with isolated monosomy of 5p. A recent study suggests this may not be the case where a trisomy of chromosome 4q is involved.

Most cases involve total loss of the most distant 10-20% of the material on the short arm. Fewer than 10% of cases have other rare cytogenetic aberrations (e.g., interstitial deletions, mosaicisms, rings and "de novo" translocations). The deleted chromosome 5 is paternal in origin in about 80% of "de novo" cases. Loss of a small region in band 5p15.2 (cri du chat critical region) correlates with all the clinical features of the syndrome with the exception of the catlike cry, which maps to band 5p15.3 (catlike critical region). The results suggest that 2 noncontiguous critical regions contain genes involved in this condition's cause. Two genes in these regions, Semaphorine F (SEMA5A) and delta catenin (CTNND2), are potentially involved in cerebral development. The deletion of the telomerase reverse transcriptase (hTERT) gene localized in 5p15.33 may contribute to the phenotypic changes in cri du chat syndrome as well.