Abstract
Objective: To report the clinical manifestations and total exon detection results of one case of MYSM1 gene complex heterozygosity mutation of bone marrow failure syndrome 4 and the results of total exon detection of her family to provide a case phenotype for the early diagnosis of bone marrow failure syndrome 4. Methods: A 1-month-old girl with severe anemia was sequenced with trio-WES. Similarly, the family was also sequenced with tribe-WES to confirm the molecular diagnosis. BWA, GATK, and other software were used for annotation analysis of sequencing results. After polymerase chain reaction, Sanger sequencing was performed by ABI3730 sequencer to verify the target sequence. Moreover, the verification results were obtained by the sequence analysis software. The clinical diagnosis of this girl was reported and the relevant pieces of literature were reviewed. Results: The girl presented with pancytopenia, polydactylism, nonspecific white matter changes, and cysts. However, CD3(-)CD19(+) B decreased. The child was identified with MYSM1 complex heterozygous mutation by whole-exome sequencing, NM_001085487.2:c.1607_c.1611delAAGAG and c.1432C>T, which was respectively inherited from his parents. Genealogy verification confirmed that the c.1432C>T mutation carried by the father was from the grandfather (father's father) , whereas the c.1607_c.1611delAAGAG mutation carried by the mother was from the grandfather (mother's father) , whereas the grandmothers, aunts, and uncle did not carry the mutation. The child was diagnosed with BMFS4 combined with clinical phenotypic and molecular genetic findings. Conclusion: This case provides a case phenotype for the early diagnosis of BMFS4 and extends the pathogenicity variation and phenotype spectrum of the MYSM1 gene. The newly discovered pathogenic variant of MYSM1 c. 1607_c.1611delAAGAG has not been reported at home or abroad.