An exon-skipping mutation in the btk gene of a patient with X-linked agammaglobulinemia and isolated growth hormone deficiency.

摘要: X-linked agammaglobulinemia (XLA) is an inherited immunodeficiency disease associated with a block in differentiation from pre-B to B cells. The XLA gene encodes 659 amino acids cytoplasmic protein tyrosine kinase named btk (Bruton's kinase). few alterations so far reported patients are heterogenous and distributed all domains of the protein. They appear be responsible for range cell disorders variable severity. Rare families which together isolated growth hormone deficiency (IGHD) have been reported. Genetic analysis has shown that this association maps same region X chromosome as XLA, but whether two phenotypes caused by common or different developmental biochemical mechanism unknown. We analyzed patient IGHD. RT-PCR transcripts, sequencing data obtained cDNA genomic DNA vitro splicing assays showed intronic point mutation (1882 + 5G-->A) skipping exon located domain. This exon-skipping event results frameshift leading premature stop codon 14 downstream, loss last 61 residues carboxy-terminal end Although we studied sporadic case, suggest alteration might cause unusual phenotype.