[Clinical and gene research of X-linked lymphoproliferative disease in a Chinese family].

OBJECTIVE: To verify the pathogenesis in Chinese and to investigate the genetic rule of X-linked lymphoproliferative disease (XLP) therein.

METHODS: The case history of a proband of XLP, male, aged 1 year and 5 months, who died 40 days after hospitalization, was reviewed. Fourteen his family members were interviewed for the development history, anamnesis, and underwent physical examination. Single-strand conformation polymorphism (SSCP-PCR) and sequencing were used to detect the SH2D1A mutation among the elder sister, younger brother, and parents of the poband.

RESULTS: The proband and his elder brother suffered with virus-associated hemophagocytic syndrome and both died in 40 days after the disease coming on in the last two years in succession. The second exon of SH2D1A of the younger brother of the proband showed a nonsense mutation in SH2D1A gene: the C-T nucleotide substitution at nucleotide position 462 result in a stop codon and pre-mature termination of protein synthesis. The mother was proved as mutation heterozygote of the C and T nucleotide on the same site. The other members of the family were proved normal. The clinical manifestation of the younger brother of the proband was Langerhans cell histiocytosis.

CONCLUSION: Langerhans cell histiocytosis may be a new clinical phenotype of XLP. The gene of SH2D1A is responsible for the disease of XLP in Chinese too. The newly developed method of SH2D1A mutation analysis may be suitable in the diagnosis of XLP in Chinese.