Difficult diagnosis of the fragile X syndrome made possible by direct detection of DNA mutations

J Tarleton; S Wong; D Heitz; C Schwartz

doi:10.1136/jmg.29.10.726

Difficult diagnosis of the fragile X syndrome made possible by direct detection of DNA mutations

J Med Genet. 1992 Oct;29(10):726-9. doi: 10.1136/jmg.29.10.726.

Authors

J Tarleton¹, S Wong, D Heitz, C Schwartz

Affiliation

¹ Greenwood Genetic Center, DNA Diagnostic Laboratory, South Carolina 29646.

Abstract

Genetic recombination near the fragile X locus (Xq27.3) has frequently been a problem in linkage studies of families in which the fragile X is segregating. This case report illustrates the resolution of a difficult situation in a fragile X family for whom cytogenetic studies were inconclusive and where recombination had twice confounded attempts at prenatal DNA diagnosis by RFLP analysis. Using a newly developed DNA probe, StB12.3, for direct detection of DNA instability in the fragile X locus, the presence of the fragile X was ascertained definitively in a prenatal DNA sample.

Publication types

Case Reports

MeSH terms

Blotting, Southern
DNA / genetics
DNA Probes / genetics*
Female
Fragile X Syndrome / diagnosis*
Genetic Linkage / genetics
Humans
Male
Mutation / genetics
Pedigree
Polymorphism, Restriction Fragment Length
Prenatal Diagnosis / methods*

Substances

DNA Probes
DNA