Mapping a Gene for Familial Situs Abnormalities to Human Chromosome
Xq24-q27.1
B. Casey, M. Devoto, K.L. Jones, A. Ballabio
Nature Genetics , 5(4), 403--487 (1993 Dec)
Abstract
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.
