Introduction: Wiskott-Aldrich syndrome (WAS) is an X-linked recessive immunodeficiency caused by WASP mutations. Identification of novel WASP mutations may help understand uncovered pathogenesis. We here noticed a rare case with a novel WASP mutation, which was also detected in his mother and grandmother. This article aimed to detect the genetic features of a WAS family and determine the source of the completely new mutation. Case presentation: This Chinese male infant was admitted to our department at postnatal day 7. He was found thrombocytopenia for 4 days. The family history documented that his two uncles both died in infancy due to repeated infections; his aunt had experienced 2 pregnancies, and both resulted in unexplained abortion. After 18-day treatment, his parents signed the request to discharge. The infant finally died at 9 months old. A novel heterozygous mutation in the exon 9 was found on his X chromosome, that c.928C>T resulting in amino acid changes p.Q310X. This mutation was revealed to be derived from his grandmother to his mother. Conclusion: In conclusion, a novel mutation (c.928C>T) was found in our male infant patient, as well as his mother and grandmother. The patient died from uncontrollable WAS symptoms, as the two boys of his grandmother did. Early detection and diagnosis of new mutation may reduce complications and increase the life expectancy of WAS patients. Prenatal DNA sequencing could be recommended to avoid birth of WAS in particular for male fetuses.