Chromosome 15 (human)

Chromosome 15 (human) is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 15 spans about 101 million base pairs (the building blocks of DNA) and represents between 3 and 3.5 percent of the total DNA in cells.

Genetic Features

Chromosome 15 houses between 600 to 700 genes that are responsible for a variety of bodily functions and developmental processes. This chromosome is known for its role in the development of the central nervous system, the metabolism of amino acids, and the processing of hormones. It also contains regions that are crucial for normal muscle function and the maintenance of the skeletal system.

Genetic Disorders

Several genetic disorders are associated with mutations or structural abnormalities in chromosome 15, including but not limited to:

• Prader-Willi syndrome (PWS) and Angelman syndrome (AS) - These are distinct disorders that result from the loss of function or deletion of genes in the 15q11-q13 region. The parent of origin affects the syndrome that presents; PWS is associated with loss of function of genes inherited from the father, while AS results from the loss of function of genes inherited from the mother.
• Marfan syndrome - While primarily associated with mutations in the FBN1 gene on chromosome 15, this condition affects the body's connective tissue, leading to symptoms in the heart, eyes, and skeleton.
• Tay-Sachs disease - Caused by a mutation in the HEXA gene on chromosome 15, this genetic disorder results in the destruction of nerve cells in the brain and spinal cord.

Unique Characteristics

Chromosome 15 is notable for containing several regions of genomic imprinting, a genetic phenomenon where the expression of genes depends on the parent from whom the gene is inherited. This is particularly relevant in the case of Prader-Willi syndrome and Angelman syndrome, as mentioned above.

Additionally, chromosome 15 has a high level of genetic variation and contains numerous single nucleotide polymorphisms (SNPs) that have been linked to various diseases and conditions, as well as to differences in drug metabolism.

Research

Ongoing research on chromosome 15 aims to further understand the complex relationship between its genetic variations and the development of diseases. Studies on the epigenetic regulation of genes on chromosome 15 are also of significant interest, as they may provide insights into new therapeutic approaches for managing genetic disorders.