Novel compound heterozygous mutations in TELO2 in an infant with You-Hoover-Fong syndrome: A case report and literature review

We report here the clinical diagnosis and treatment and genetic mutations of an infant with You-Hoover-Fong syndrome (YHFS). The relevant literature review was conducted. A female infant aged 17 months was admitted to Nanhai Affiliated Maternity and Children’s Hospital of Guangzhou University of Chinese Medicine due to “global development delay complicated with postnatal growth retardation for more than 1 year.” The infant was diagnosed with YHFS due to the onset of extremely severe mental retardation, microcephaly, abnormal hearing, severe protein–energy malnutrition, congenital cataract, cleft palate (I°), congenital atrial septal defect, brain atrophy, hydrocephalus, and brain hypoplasia. The whole exon sequencing revealed two compound heterozygous mutations, including a likely pathogenic TELO2 variant, c.2245A > T (p.K749X) from her mother and an uncertain variant, c.2299C > T (p.R767C) from her father, validated by Sanger sequencing. After bilateral cataract surgery, the infant obtained better visual acuity and showed more responses and interactions with her parents. Diagnosis and treatment of this case prompt that these TELO2 variants have not been reported, deepening the understanding of the molecular and genetic mechanism of YHFS in clinical practice.