Linkage studies exclude the AT-V gene(s) from the translocation breakpoints in an AT-V patient.
An 8-year-old girl with severe microcephaly of prenatal onset, borderline intelligence, defects of skin pigmentation, deficiency of both humoral and cellular immunity, a normal serum alpha-fetoprotein level and hypersensitivity to ionizing irradiation is described. Spontaneous chromosomal breakage in lymphocytes together with the clinical presentation led to the diagnosis of ataxia telangiectasia variant (AT-V). In addition, the patient carried a constitutional translocation of paternal origin: 46,XX,t(3;7)(q12;q31.3) pat. In subsequent linkage and haplotype studies in 12 AT-V families with microsatellite markers from each of the translocation breakpoint regions, we could clearly exclude the localization of an AT-V gene to these regions.
Chrzanowska
K
K
Department of Genetics, The Children's Memorial Health Institute, Warsaw, Poland.
Stumm
M
M
Bialecka
M
M
Saar
K
K
Bernatowska-Matuszkiewicz
E
E
Michalkiewicz
J
J
Barszcz
S
S
Reis
A
A
Wegner
R D
RD
D001260:Ataxia Telangiectasia / Q000235:genetics* / Q000503:physiopathology; D002648:Child; D002893:Chromosomes, Human, Pair 3; D002897:Chromosomes, Human, Pair 7; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D007621:Karyotyping; D014178:Translocation, Genetic