What does Isodicentric mean?

Isodicentric chromosome 15 syndrome is a chromosome abnormality that affects many different parts of the body. As the name suggests, people with this condition have an extra chromosome (called an isodicentric chromosome 15) which is made of two pieces of chromosome 15 that are stuck together end-to-end.

What causes Dup15q?

Dup15q syndrome is caused by chromosome abnormalities that result in at least one extra copy of a region of chromosome 15 called 15q11. 2-q13. 1. In particular, the condition arises only if the chromosome abnormality occurs on the copy of the chromosome inherited from the mother (the maternal copy).

How does Isodicentric chromosome happen?

The formation of isodicentric Y chromosomes is believed to result from intrachromosomal recombination or the fusion between sister chromatids following the chromosomal break of the Y chromosome [3]. The sites where breakage and fusion occur at the Y chromosome vary greatly [4].

How is Dup15q diagnosed?

Diagnosis. Genetic testing methods such as fluorescence in situ hybridization (FISH) and chromosomal microarray are available for diagnosing Dup15q syndrome and similar genetic disorders. With the increase in genetic testing availability, more often duplications outside of the 15q11. 2-13.1 region are being diagnosed.

How do you get trisomy 15?

In most cases, Chromosome 15, Distal Trisomy 15q is due to a chromosomal “balanced translocation” in one of the parents. Translocations occur when regions of certain chromosomes break off and are rearranged, resulting in shifting of genetic material and an altered set of chromosomes.

How common is trisomy 15?

Chromosome 15, Distal Trisomy 15q is an extremely rare chromosomal disorder that is thought to affect males approximately twice as often as females. Since the disorder was originally described in the medical literature in 1974 (A. Fujimoto), more than 30 cases have been reported in the literature.