RESUMO
The SHOX (short-stature homeobox-containing) gene encodes isoforms of a homeodomain transcription factor important in human limb development. SHOX haploinsufficiency has been implicated in three human growth disorders: Turner syndrome, idiopathic short stature, and Leri-Weill dyschondrosteosis. Langer mesomelic dysplasia is thought to be the homozygous form of dyschondrosteosis. However, complete SHOX deficiency has not been demonstrated for any postnatal patient with the classic Langer phenotype. We studied four adults and one child with Langer mesomelic dysplasia. SHOX abnormalities were detected in all five probands. One was a homozygote or hemizygote and two were compound heterozygotes. The homozygous or hemizygous mutation was in exon 6a, implying that the SHOXa isoform is essential for normal skeletal development. These findings confirm clinical inferences that Langer mesomelic dysplasia is the homozygous form of Leri-Weill dyschondrosteosis and add to our understanding of genotype/phenotype relationships in SHOX deficiency disorders.
Assuntos
Proteínas de Homeodomínio/genética , Osteocondrodisplasias/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Análise Mutacional de DNA , DNA Complementar/química , DNA Complementar/genética , Feminino , Deleção de Genes , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Mutagênese Insercional , Osteocondrodisplasias/patologia , Mutação Puntual , Proteína de Homoeobox de Baixa EstaturaRESUMO
Migraine is a complex neurovascular disorder with substantial evidence supporting a genetic contribution. Prior attempts to localize susceptibility loci for common forms of migraine have not produced conclusive evidence of linkage or association. To date, no genomewide screen for migraine has been published. We report results from a genomewide screen of 50 multigenerational, clinically well-defined Finnish families showing intergenerational transmission of migraine with aura (MA). The families were screened using 350 polymorphic microsatellite markers, with an average intermarker distance of 11 cM. Significant evidence of linkage was found between the MA phenotype and marker D4S1647 on 4q24. Using parametric two-point linkage analysis and assuming a dominant mode of inheritance, we found for this marker a maximum LOD score of 4.20 under locus homogeneity (P=.000006) or locus heterogeneity (P=.000011). Multipoint parametric (HLOD = 4.45; P=.0000058) and nonparametric (NPL(all) = 3.43; P=.0007) analyses support linkage in this region. Statistically significant linkage was not observed in any other chromosomal region.