[Pedigree investigation and genetic analysis of a case with Vel heterozygous deletion mutation]

To analyze an individual with SMIM1 c.64_80 heterozygous deletional mutation and his family members.

Based on the molecular basis of Vel negative blood type, PCR primers specific for SMIM1 wild-type allele and c.64_80del allele were designed. PCR-sequence specific primer (PCR-SSP) and Sanger sequencing were employed to determine the genotype of all subjects. Inheritance of the Vel blood group system was investigated by pedigree analysis.

PCR-SSP and DNA sequencing demonstrated that the proband was heterozygous for the SMIM1 c.64_80del allele. Pedigree investigation showed that his father had the same mutation, while his mother and elder sister were of wide type. No individual with homozygous c.64_80del allele was found.

PCR-SSP and DNA sequencing confirmed that the proband was heterozygous for the c.64_80del mutation. The mutation inherits form his father.