RESUMO
<p><b>OBJECTIVE</b>To provide genetic diagnosis and counseling for patients from two families affected with X-linked hypohidrotic ectodermal dysplasia.</p><p><b>METHODS</b>Potential mutation of the ED1 gene was screened by DNA sequencing. For family 1, multiplex ligation-dependent probe amplification (MLPA) analysis and haplotyping of ED1 gene were also carried out for prenatal diagnosis.</p><p><b>RESULTS</b>For the patient from family 1, deletion of the exon 1 of the ED1 gene and 2 short tandem repeat(STR) sites (DXS8269 and DXS1422) were detected. His daughter was carrier of the deletion. Upon prenatal diagnosis, the fetus was confirmed to be a normal male, for whom the haplotype of ED1 gene has differed from that of the proband. In family 2, a c.463C>T mutation in exon 3 of the ED1 gene was detected in the proband, whose mother was heterozygous for the same mutation.</p><p><b>CONCLUSION</b>The deletion (exon 1) and missense (R155C) mutation in ED1 gene have probably underlied the disease in the two families. During prenatal diagnosis, it may be necessary to obtain precise results through combining mutation detection and haplotype analysis of the ED1 gene.</p>