Chiang JA, Shumakova V, Greenfield K, Patterson M and Boxer OR
Background: SET domain containing 5 (SETD5) gene variants have been linked to developmental delays, craniofacial abnormalities, and intellectual disability (ID). Prior research examining the phenotypic presentation of individuals with SETD5 variations has been based largely on a male-dominated cohort and case studies. Evidence of a possible protective effect in females prompts the need for additional research on the neuropsychological presentation of females with a SETD5 variation. The current study aims to initiate this effort by discussing the neurocognitive profile of a right-handed 7-year-old Caucasian female with a diagnosed SETD5 variation.
Methods and findings: The patient was referred for neuropsychological evaluation due to reported reading, writing, and fine motor difficulties. She presented with distinct dysmorphic features: head circumference <1st percentile, syndactyly of toes, clinodactyly of fifth fingers, and a long smooth philtrum with thin upper lip. Interpersonally, the patient was highly social. Cognitive testing revealed low average intelligence, with intact verbal/language functioning and impaired nonverbal/fluid reasoning abilities. Deficits were also observed in fine motor dexterity, visuomotor integration, attention, and broad academic achievement. The patient was ultimately referred for genetic testing, which revealed a de novo SETD5 frame shift variant resulting in a truncation of the gene copy near the end of the gene.
Conclusion: This case study provides evidence for phenotypic differences between males and females with SETD5 gene variations. While males exhibit ID, females may present with significant deficits in nonverbal reasoning skills. Females may also display more fully developed social skills and a lack of repetitive stereotyped behaviors. Further research is warranted to clarify the unique presentation among females with SETD5 variations to better inform diagnosis and treatment planning.