We report the first Far Eastern case of a Korean child with familial hemophagocytic lymphohistiocytosis (HLH) caused by a novel syntaxin 11 (STX11) mutation. A 33-month-old boy born to non-consanguineous Korean parents was admitted for intermittent fever lasting one week, pancytopenia, hepatosplenomegaly, and HLH in the bone marrow. Under the impression of HLH, genetic study revealed a novel homozygous missense mutation of STX11: c.650T>C, p.Leu217Pro. Although no large deletion or allele drop was identified, genotype analysis demonstrated that the homozygous c.650T>C may have resulted from the duplication of a maternal (unimaternal) chromosomal region and concurrent loss of the other paternal allele, likely caused by meiotic errors such as two crossover events. A cumulative study of such novel mutations and their effects on specific protein interactions may deepen the understanding of how abnormal STX1 expression results in deficient cytotoxic function.
Alleles ; Amino Acid Sequence ; Asian Continental Ancestry Group/*genetics ; Base Sequence ; Bone Marrow/metabolism ; Child, Preschool ; Comparative Genomic Hybridization ; DNA Mutational Analysis ; Genotype ; Haplotypes ; Homozygote ; Humans ; Lymphohistiocytosis, Hemophagocytic/*genetics/pathology ; Male ; Molecular Sequence Data ; Mutation, Missense ; Pedigree ; Qa-SNARE Proteins/*genetics ; Republic of Korea ; Sequence Alignment