Abstract
A child with maple syrup urine disease type 2 (MSUD2) was found to be homozygous for a 10-bp MSUD2-gene deletion on chromosome 1. Both purported parents were tested, and neither carries the gene deletion. Polymorphic simple-sequence repeat analyses at 15 loci on chromosome 1 and at 16 loci on other chromosomes confirmed parentage and revealed that a de novo mutation prior to maternal meiosis I, followed by nondisjunction in maternal meiosis II, resulted in an oocyte with two copies of the de novo mutant allele. Fertilization by a sperm that did not carry a paternal chromosome 1 or subsequent mitotic loss of the paternal chromosome 1 resulted in the propositus inheriting two mutant MSUD2 alleles on two maternal number 1 chromosomes.
Original language | English (US) |
---|---|
Pages (from-to) | 750-754 |
Number of pages | 5 |
Journal | American Journal of Human Genetics |
Volume | 67 |
Issue number | 3 |
DOIs | |
State | Published - 2000 |
ASJC Scopus subject areas
- Genetics
- Genetics(clinical)