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Distal trisomy 10 is a rare chromosomal disorder that causes several physical defects and intellectual disability. [ 5 ] 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.
The most common aneuploidy that infants can survive with is trisomy 21, which is found in Down syndrome, affecting 1 in 800 births. Trisomy 18 (Edwards syndrome) affects 1 in 6,000 births, and trisomy 13 (Patau syndrome) affects 1 in 10,000 births. 10% of infants with trisomy 18 or 13 reach 1 year of age. [7]
People with Down syndrome experience a wide range of emotions. [51] While people with Down syndrome are generally happy, [52] symptoms of depression and anxiety may develop in early adulthood. [9] Children and adults with Down syndrome are at increased risk of epileptic seizures, which occur in 5–10% of children and up to 50% of adults. [9]
The number of chromosomes in the cell where trisomy occurs is represented as, for example, 2n+1 if one chromosome shows trisomy, 2n+1+1 if two show trisomy, etc. [2] "Full trisomy", also called "primary trisomy", [2] means that an entire extra chromosome has been copied. "Partial trisomy" means that there is an extra copy of part of a chromosome.
Trisomy 13 was first observed by Thomas Bartholin in 1657, [11] [12] but the chromosomal nature of the disease was ascertained by Dr. Klaus Patau and Dr. Eeva Therman in 1960. [13] The disease is named in Patau's honor. In England and Wales during 2008–09, there were 172 diagnoses of Patau syndrome (trisomy 13), with 91% of diagnoses made ...
1 in 12,000 to 20,000 people [6] Angelman syndrome ( AS ) is a genetic disorder that mainly affects the nervous system . [ 6 ] Symptoms include a small head and a specific facial appearance, severe intellectual disability , developmental disability , limited to no functional speech, balance and movement problems, seizures, and sleep problems. [ 6 ]
An isochromosome is an unbalanced structural abnormality in which the arms of the chromosome are mirror images of each other. [1] The chromosome consists of two copies of either the long (q) arm or the short (p) arm because isochromosome formation is equivalent to a simultaneous duplication and deletion of genetic material .
The frequency is approximately 3-4 per 10,000 people, and 1 in 300 people with intellectual disability. [2] Marker chromosomes typically occur in addition to the standard 46 chromosomes, making it a partial trisomy or tetrasomy supernumerary chromosome. [4]