The autosomal recessive Kenny-Caffey syndrome locus maps to chromosome 1q42-q43

Kenny-Caffey syndrome (KCS) is an osteosclerotic bone dysplasia with associated hypocalcemia and ocular abnormalities. Both autosomal dominant (MIM127000) and autosomal recessive (MIM244460) inheritance patterns have been described. Using eight consanguineous Kuwaiti kindreds, a genome-wide search for linkage to the gene causing the autosomal recessive form of KCS was performed with polymorphic short tandem repeat markers. Significant linkage to a locus situated at chromosome 1q42 --> q43 with a maximal two-point lod score of 13.30 with marker D1S2649 was obtained. Haplotype analysis of flanking markers identified recombination events defining the KCS locus to a region between markers D1S2800 on the centromeric boundary and D1S2850 on the telomeric boundary, an approximately 4-cM interval. All affected individuals in these unrelated kindreds were homozygous for identical alleles at markers D1S2649 and D1S235, suggesting a single ancestral mutation underlying the disease in these families. Haploinsufficiency at 22q11, reported in another consanguineous KCS kindred, was not documented in these families.