RESUMO
Netherton syndrome (NS [MIM 256500]) is a rare and severe autosomal recessive disorder characterized by congenital ichthyosis, a specific hair-shaft defect (trichorrhexis invaginata), and atopic manifestations. Infants with this syndrome often fail to thrive; life-threatening complications result in high postnatal mortality. We report the assignment of the NS gene to chromosome 5q32, by linkage analysis and homozygosity mapping in 20 families affected with NS. Significant evidence for linkage (maximum multipoint LOD score 10.11) between markers D5S2017 and D5S413 was obtained, with no evidence for locus heterogeneity. Analysis of critical recombinants mapped the NS locus between markers D5S463 and D5S2013, within an <3.5-cM genetic interval. The NS locus is telomeric to the cytokine gene cluster in 5q31. The five known genes encoding casein kinase Ialpha, the alpha subunit of retinal rod cGMP phosphodiesterase, the regulator of mitotic-spindle assembly, adrenergic receptor beta2, and the diastrophic dysplasia sulfate-transporter gene, as well as the 38 expressed-sequence tags mapped within the critical region, are not obvious candidates. Our study is the first step toward the positional cloning of the NS gene. This finding promises a better understanding of the molecular mechanisms that control epidermal differentiation and immunity.
Assuntos
Mapeamento Cromossômico , Cromossomos Humanos Par 5/genética , Cabelo/anormalidades , Hipersensibilidade Imediata/genética , Ictiose/genética , Adolescente , Adulto , Criança , Pré-Escolar , Citocinas/genética , Feminino , Genes Recessivos/genética , Cabelo/metabolismo , Haplótipos/genética , Homozigoto , Humanos , Células Híbridas/metabolismo , Hipersensibilidade Imediata/fisiopatologia , Ictiose/fisiopatologia , Lactente , Recém-Nascido , Escore Lod , Masculino , Repetições de Microssatélites/genética , Linhagem , RNA Mensageiro/genética , Recombinação Genética/genética , SíndromeRESUMO
INTRODUCTION: Bejel (endemic syphilis) is usually encountered in children living in intertropical areas, although imported cases have been exceptionally reported in Europe. OBSERVATION: We report on a young girl aged 5 diagnosed in France, who had painless stomatitis and enlarged cervical nodes. Diagnosis of bejel was confirmed by serology, and spirochetes were shown inside mucous patches by biopsy specimen silver staining. Favorable clinical and serological outcome occurred following benzathin-penicillin therapy. Contamination is likely to have occurred in Mali where she had been living for several years, but secondary stage manifestations only appeared in France, where she was living for several months. DISCUSSION: Although rare in France, bejel should not be overlooked in children originating from countries where endemic syphilis has a high prevalence.
