Mapping a gene for familial situs abnormalities to human chromosome Xq24-q27.1.
Ambiguous abdominal situs, asplenia/polysplenia and severe cardiac malformations characterize heterotaxy in humans. These anomalies result from the inability of the developing embryo to establish normal left-right asymmetry. We have studied an interesting family in which the heterotaxy phenotype segregates as an X-linked recessive trait. In order to map the heterotaxy locus (HTX), we have analysed 39 family members using highly-polymorphic microsatellite markers from the X chromosome. One of these markers, DXS994, shows no recombination with the disease locus in 20 informative meioses. Linkage analysis results in a maximum lod score of 6.37. Current genetic and physical mapping data assign the order of loci in Xq24-q27.1 as cen-DXS1001-(DXS994, HTX)-DXS984-tel. These results establish the first mapping assignment of situs abnormalities in humans.
Casey
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Department of Pathology, Baylor College of Medicine, Houston, Texas 77030.
Devoto
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Jones
K L
KL
Ballabio
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A
D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D005190:Family; D008040:Genetic Linkage; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D010375:Pedigree; D011110:Polymorphism, Genetic; D012729:Sex Chromosome Aberrations / Q000235:genetics; D012857:Situs Inversus / Q000235:genetics*; D014960:X Chromosome