RESUMO
Objective To report a case of X-linked ichthyosis complicated by Mal de Meleda,and to identify the gene mutations.Methods Clinical data were collected from the patient,and peripheral blood samples were obtained from the patient,his parents and 100 unrelated healthy people who served as controls.Genomic DNA was extracted from these blood samples,and PCR was performed to amplify all the exons and their flanking sequences of the SLURP-1 and STS genes.All the amplification products were analyzed by agarose gel electrophoresis,and amplification products of the SLURP-1 gene were analyzed by DNA sequencing.Results The patient presented with regularly-arranged polygonal brown or black scales all over the trunk and limbs,erythematous hyperkeratotic lesions on the palms and soles,elbows and knees,inguinal and perianal regions,which extended to the dorsa of the hands and feet.Then,the patient was diagnosed with X-linked ichthyosis complicated by Mal de Meleda.Genetic testing showed complete deletion of the STS gene,and a homozygous mutation (c.286C ＞ T) at position 286 in exon 3 of the SLURP-1 gene,which led to the formation of a premature termination codon at amino acid position 96 (p.R96*).His parents were heterozygous carriers of the mutation (c.286C ＞ T).No mutation was found in the unrelated healthy controls.Conclusion The complete deletion of the STS gene and the homozygous nonsense mutation in the SLURP-1 gene may be the reason for X-linked ichthyosis complicated by Mal de Meleda in the patient.
RESUMO
Mal de Meleda (MDM), also known as keratoderma palmoplantaris transgrediens, is a rare inherited form of palmoplantar keratoderma. It is characterized by erythema and hyperkeratosis of the palms and soles, extending to the dorsal aspects of the hands and feet. A 15-year-old Korean female presented with sharply demarcated hyperkeratotic plaques on the palms and soles, which extended to the dorsal surfaces of the hands and feet, in a "glove-and-socks" distribution. The histopathologic study showed marked hyperkeratosis, acanthosis, and normogranulosis, without epidermolysis. Her genetic study detected compound heterozygous mutation in exon 3 of the ARS gene encoding SLURP-1. Family history did not reveal any other affected members and no consanguineous relationship was found. In view of these findings, we diagnosed this case as the first reported sporadic case of MDM in Korea, the farthest location from the endemic island of Meleda.