Cohen syndrome in two patients from China

BACKGROUND: Cohen syndrome (CS; OMIM 216550) is a rare syndrome with evident clinical heterogeneity. The diverse phenotype comprises early‐onset hypotonia and developmental delays, intellectual disabilities, microcephaly, hypermobile joints, neutropenia, myopia, and characteristic facial features. The disease is rarely reported. Vacuolar Protein Sorting 13 Homolog B (VPS13B; OMIM 607817) is the only causative gene of CS. METHODS: Blood samples sourced from both siblings and parents were sent to identify mutations by trio‐WES, and changes in the patient's condition were understood through consultation data and follow‐up. RESULTS: We reported two siblings affected by developmental delay, microcephaly, intellectual disability, and facial features. The siblings' WES detected compound heterozygous variants in the exon region of VPS13B (NM_017890): c.9337A>T and c.8551A>C. CONCLUSION: Two individuals were diagnosed with CS by genetic testing and clinical features. In addition, we conduct a brief review of the reports on the Chinese population with CS and reinforce the understanding of the correlation between genotype–phenotype.