Some Single-Gene Defects for Which Genetic Tests

Some Single-Gene Defects For Which Genetic Tests Are Available
Disease Gene Mutation Description
Achondroplasia FGFR3 gene. 99% of patients have a C to A point Abnormal bone growth
mutation at nucleotide 1138 (G380R substitution)
Hereditary breast/ovarian cancer BRCA1 and BRCA2 genes‘ Deletions, duplications, Predisposition to breast, ovarian, pros
and point mutations tate, and other cancers
Duchenne muscular dystrophy DMD gene. Point mutations, deletions, insertions, Early-onset progressive muscular weak-
splicing mutations ness, heart disease
Fragile-X syndrome FMR7 gene. Primarily expanded trinucleotide (CGG) Mental retardation, developmental
repeats and loss offunction disorders
Friedrich ataxia FXN gene. 98% ofcases have expanded trinucleotide Ataxia, muscle weakness, spasticity, heart
(GAA) repeats in intron 1 and other organ dysfunctions
Hemophilia A F8 gene. Point mutations, insertions, deletions, Factoerll blood-clotting defects, bleeding
InverSIons
Huntington disease HTT(HD) gene. Trinucleotide (CAG) repeat Midlife onset ofprogressive motor and
expansions cognitive disorders
Lesch-Nyhan syndrome HPRT7 gene‘ Point mutations, deletions, Developmental, motor, and cognitive
duplications disorders
Marfan syndrome FBN7 gene. Point mutations, splicing mutations, Connective tissue disorders afFecting
deletions numerous organs
Polycystic kidney disease, PKDT and PKDZ genes. Sequence variants, partial or Cysts in kidney, liver, and other organs,
dominant whole»gene deletions and duplications vascular abnormalities
Sickle—cell disease HBB gene. Point mutation leading to Glu to Val Early-onset anemia
substitution at amino acid 6