X linked myotubular myopathy (MTM1) maps between DXS304 and DXS305, closely linked to the DXS455 VNTR and a new, highly informative microsatellite marker (DXS1684).
The locus for X linked recessive myotubular myopathy (MTM1) has previously been mapped to Xq28 by linkage analysis. We report two new families that show recombination between MTM1 and either DXS304 or DXS52. These families and a third previously described recombinant family were analysed with two highly polymorphic markers in the DXS304-DXS52 interval, the DXS455 VNTR and a newly characterised microsatellite, DXS1684 (82% heterozygosity). These markers did not recombine with MTM1 in the three families. Together with the recent mapping of an interstitial X chromosome deletion in a female patient with moderate signs of myotubular myopathy, our data suggest the following order of loci in Xq28: cen-DXS304-(DXS455, MTM1)-DXS1684-DXS305-DXS52-tel. This considerably refined localisation of the MTM1 locus should facilitate positional cloning of the gene. The availability of highly polymorphic and very closely linked markers will markedly improve carrier and prenatal diagnosis of MTM1.
Dahl
N
N
Laboratoire de Génétique Moléculaire des Eucaryotes du CNRS, Strasbourg, France.
Samson
F
F
Thomas
N S
NS
Hu
L J
LJ
Gong
W
W
Herman
G
G
Laporte
J
J
Kioschis
P
P
Poustka
A
A
Mandel
J L
JL
D001483:Base Sequence; D017931:DNA Primers; D004276:DNA, Satellite / Q000235:genetics*; D005260:Female; D006580:Genetic Carrier Screening; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D008297:Male; D018598:Minisatellite Repeats; D008969:Molecular Sequence Data; D009135:Muscular Diseases / Q000235:genetics*; D010375:Pedigree; D014960:X Chromosome
D017931:DNA Primers; D004276:DNA, Satellite; D005819:Genetic Markers