Localization of autosomal recessive congenital cataracts in consanguineous Pakistani families to a new locus on chromosome 1p.
OBJECTIVE
To identify the disease locus for autosomal recessive congenital cataracts in two consanguineous Pakistani families.


METHODS
Two Pakistani families were ascertained, ophthalmologic examination including slit lamp biomicroscopy was performed on all members, blood samples were collected and DNA was extracted. A genome-wide scan was performed using 382 polymorphic microsatellite markers on genomic DNA from affected and unaffected family members. Two-point logarithm of odds (LOD) scores were calculated using the LINKAGE program package.


RESULTS
All the affected individuals of family PKCC009 show bilateral membranous cataract, whereas the affected individuals of family PKCC039 show bilateral posterior sub-capsular cataract. Other ocular abnormalities include corneal opacities, microcornea and nystagmus in the affected individuals of PKCC009. Maximum two point LOD scores were obtained with D1S186 (4.14 at theta = 0), D1S432 (4.01 at theta = 0), D1S2892 (4.11 at theta = 0), and D1S2797 (4.07 at theta = 0) for family PKCC009 and with D1S496 (4.73 at theta = 0), D1S2892 (4.34 at theta = 0), D1S3721 (4.83 at theta = 0), and D1S2797 (4.32 at theta = 0) for family PKCC039. The common linked region, 20.76 cM (20.80 Mb), is flanked by markers D1S2729 and D1S2890 and co-segregates with the disease in both families, placing the disease locus on chromosome 1p34.3-p32.2.


CONCLUSIONS
Linkage analysis of autosomal recessive cataracts in two consanguineous Pakistani families localizes a novel locus for autosomal recessive congenital cataract on chromosome 1p.
Butt
Tariq
T
National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.
Yao
Wenliang
W
Kaul
Haiba
H
Xiaodong
Jiao
J
Gradstein
Libe
L
Zhang
Yan
Y
Husnain
Tayyab
T
Riazuddin
Sheikh
S
Hejtmancik
J Fielding
JF
Riazuddin
S Amer
SA
D044466:Asian People / Q000235:genetics*; D002386:Cataract / Q000151:congenital* / Q000235:genetics*; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D003241:Consanguinity; D003315:Cornea / Q000002:abnormalities; D005808:Genes, Recessive; D008040:Genetic Linkage; D006801:Humans; D008126:Lod Score; D009759:Nystagmus, Pathologic / Q000235:genetics; D010154:Pakistan