Linkage analysis of Norrie disease with an X-chromosomal ornithine aminotransferase locus.
Norrie disease is a rare disease of newborn males caused by prenatal or perinatal retinal detachment, which may be associated with mental retardation, psychosis, and/or hearing loss. DXS7 (L1.28) and MAO A and B loci have been linked to the ND locus on the short arm of the X chromosome. Sequences homologous to OAT also have been mapped to the short arm of the X chromosome. We performed linkage analyses between the ND locus and one of the OAT-like clusters of sequences on the X chromosome (OATL1), using a ScaI RFLP in a ND family, and increased the previously calculated lod score (z) to over 3 (3.38; theta = 0.05). Similarly, we calculated a lod score of 4.06 (theta = 0.01) between the OATL1 and DXS7 loci. Alone, the OATL1 ScaI RFLP system is expected to be informative in 48% of females. If this system were used in combination with the DXS7 TaqI polymorphism, 71% of females would be informative for at least one of the markers and 21% would be informative for both. Because the OATL1 ScaI RFLP is a relatively common polymorphism, this system should be useful for the identification of ND carriers and affected male fetuses and newborns.
Bateman
J B
JB
Vision Genetics Center, Jules Stein Eye Institute, UCLA School of Medicine.
Kojis
T L
TL
Cantor
R M
RM
Heinzmann
C
C
Ngo
J T
JT
Spence
M A
MA
Inana
G
G
Kivlin
J D
JD
Curtis
D
D
Sparkes
R S
RS
D004247:DNA / Q000032:analysis; D015342:DNA Probes; D015252:Deoxyribonucleases, Type II Site-Specific; D008040:Genetic Linkage; D006801:Humans; D008126:Lod Score; D008297:Male; D009953:Ornithine-Oxo-Acid Transaminase / Q000235:genetics*; D010375:Pedigree; D012150:Polymorphism, Restriction Fragment Length; D012160:Retina / Q000002:abnormalities*; D012163:Retinal Detachment / Q000235:genetics; D014960:X Chromosome / Q000201:enzymology*
D015342:DNA Probes; D004247:DNA; D009953:Ornithine-Oxo-Acid Transaminase; C047020:endodeoxyribonuclease ScaI; D015252:Deoxyribonucleases, Type II Site-Specific