compound heterozygote
Individual carrying two different pathogenic variants in the same gene. Results in recessive disorder despite having different mutations on each chromosome.
Full Definition
A genetic state where an individual inherits two different pathogenic variants (mutations) in the same gene, one from each parent, resulting in a recessive genetic disorder. Unlike simple homozygotes who carry identical mutations, compound heterozygotes have distinct pathogenic variants that both affect gene function. This condition is particularly common in populations with diverse genetic backgrounds and can complicate genetic counseling as the specific combination of variants may influence disease severity or presentation. Compound heterozygosity is frequently encountered in conditions such as cystic fibrosis, where over 2,000 different CFTR mutations have been identified.
Usage
Usage note: Specify the particular variants when discussing individual cases to avoid confusion with simple heterozygosity.
In Context
- "The patient was identified as a compound heterozygote for CFTR mutations F508del and G542X." — Genetic testing report
- "Compound heterozygote status explains the milder phenotype compared to patients homozygous for the more severe variant." — Clinical genetics consultation