Clinical classification and genetic mutation study of two pedigrees with type II Waardenburg syndrome / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the molecular etiology of two pedigrees affected with type II Waardenburg syndrome (WS2) and to provide genetic diagnosis and counseling.</p><p><b>METHODS</b>Blood samples were collected from the proband and his family members. Following extraction of genomic DNA, the coding sequences of PAX3, MITF, SOX10 and SNAI2 genes were amplified with PCR and subjected to DNA sequencing to detect potential mutations.</p><p><b>RESULTS</b>A heterozygous deletional mutation c.649_651delAGA in exon 7 of the MITF gene has been identified in all patients from the first family, while no mutation was found in the other WS2 related genes including PAX3, MITF, SOX10 and SNAI2.</p><p><b>CONCLUSION</b>The heterozygous deletion mutation c.649_651delAGA in exon 7 of the MITF gene probably underlies the disease in the first family. It is expected that other genes may also underlie WS2.</p>