<unk>  is a rare human genetic disorder, caused by a chromosomal aberration in which the long ("q") arm of one copy of chromosome 15 is deleted, or<unk> ly deleted. Like other chromosomal disorders, this increases the risk of birth defects, developmental delay and learning difficulties, however, the problems that can develop depend very much on what genetic material is missing. If the mother's copy of the chromosomal region 15q11-13 is deleted, Angelman syndrome (AS) can result. The sister syndrome Prader-Willi syndrome (PWS) can result if the father's copy of the chromosomal region 15q11-13 is deleted. The smallest observed region that can result in these syndromes when deleted is therefore called the PWS/AS critical region. In addition to deletions, uniparental disomy of chromosome 15 also gives rise to the same genetic disorders, indicating that genomic imprinting must occur in this region. Deletions of regions of chromosome 15 (notably regions 15q15 and 15q22) on several types of human tumours suggest the presence of a potential tumor suppressor gene. This disorder occurs in approximately 1 in 40,000 live births
Chromosome 15q partial deletion
Chromosome 15q trisomy
Chromosome 2q deletion
2q37 monosomy
Xp11.2 duplication
Distal trisomy 10q
Partial monosomy 13q
Chromosome 5q deletion syndrome