Deletion (X)(q26.1→q28) in a proband and her mother: Molecular characterization and phenotypic-karyotypic deductions Article

cited authors

  • Tharapel, AT; Anderson, KP; Simpson, JL; Martens, PR; Wilroy, RS; Llerena, JC; Schwartz, CE

fiu authors

abstract

  • During a routine prenatal diagnosis we detected a female fetus with an apparent terminal deletion of an X chromosome with a karyotype 46,X,del(X)(q25); the mother, who later underwent premature ovarian failure, had the same Xq deletion. To further delineate this familial X deletion and to determine whether the deletion was truly terminal or, rather, interstitial (retaining a portion of the terminal Xq28), we used a combination of fluorescence in situ hybridization (FISH) and Southern analyses. RFLP analyses and dosage estimation by densitometry were performed with a panel of nine probes (DXS3, DXS17, DXS11, DXS42, DXS86, DXS144E, DXS105, DXS304, and DXS52) that span the region Xq21 to subtelomeric Xq28. We detected a deletion involving the five probes spanning Xq26-Xq28. FISH with a cosmid probe (CLH 128) that defined Xq28 provided further evidence of a deletion in that region. Analysis with the X chromosome-specific cocktail probes spanning Xpter-qter showed hybridization signal all along the abnormal X, excluding the possibility of a cryptic translocation. However, sequential FISH with the X α-satellite probe DXZ1 and a probe for total human telomeres showed the presence of telomeres on both the normal and deleted X chromosomes. From the molecular and FISH analyses we interpret the deletion in this family as 46,X,del(X)(pter→q26::qter). In light of previous phenotypic-karyotypic correlations, it can be deduced that this region contains a locus responsible for ovarian maintenance.

publication date

  • January 1, 1993

start page

  • 463

end page

  • 471

volume

  • 52

issue

  • 3