Clinical and genetic analysis of trichohepatoneurodevelopmental syndrome caused by a CCDC47 variant

Qi Yang; Xunzhao Zhou; Yeying Ling; Qiang Zhang; Shang Yi; Qiuli Chen; Shujie Zhang; Zailong Qin; Jingsi Luo

doi:10.1016/j.heliyon.2024.e27955

Clinical and genetic analysis of trichohepatoneurodevelopmental syndrome caused by a CCDC47 variant

Heliyon. 2024 Mar 14;10(6):e27955. doi: 10.1016/j.heliyon.2024.e27955. eCollection 2024 Mar 30.

Authors

Qi Yang^{1

2}, Xunzhao Zhou^{1

2}, Yeying Ling³, Qiang Zhang^{1

2}, Shang Yi^{1

2}, Qiuli Chen^{1

2}, Shujie Zhang^{1

2}, Zailong Qin^{1

2}, Jingsi Luo^{1

2}

Affiliations

¹ Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
² Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
³ Department of Neonatal Intensive Care Unit, Neonatal Medical Center, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.

Abstract

Trichohepatoneurodevelopmental syndrome is an extremely uncommon autosomal recessive disorder resulting from variants in the CCDC47 gene, which encodes a Ca2⁺-binding endoplasmic reticulum (ER) transmembrane protein. To date, only four patients with CCDC47 deficiency have been reported, all of them with homozygous truncating CCDC47 variants. For this study, a Chinese family was recruited, which included a patient diagnosed with trichohepatoneurodevelopmental syndrome. Whole exome sequencing (WES) identified the proband's novel homozygous CCDC47 variation (NM_020198: c.634C > T(p.Arg212*). The variant was confirmed to be segregating in the proband and her unaffected relatives through Sanger sequencing. The patient described exhibited a clinical phenotype similar to that of patients with the CCDC47 variant. Compared to reported cases with CCDC47 pathogenic variants, our patients showed a novel complication of hearing impairment. In addition, brain abnormalities, small feet, bilateral hip dislocation, hip dysplasia, overlapping toes, pectus excavatum, scoliosis and narrow chest were not observed in our patient. We also examined five different variations and their corresponding phenotypes from five patients, both in current and previous research. Although some clinical manifestations of trichohepatoneurodevelopmental syndrome were highly variable, the most common phenotypes observed in these patients include microcephaly, profound intellectual disability, severe global development delay, pronounced growth restriction, hypotonia, woolly hair, facial dysmorphism, respiratory and visual abnormalities, gastrointestinal abnormalities, liver dysfunction, pruritus, skeletal and limb abnormalities, congenital heart defects and immunodeficiency. The present report is the first of a Chinese infant with homozygous variant in the CCDC47 gene. We expanded the genetic and phenotypic spectrum associated with trichohepatoneurodevelopmental syndrome.

Keywords: CCDC47; Novel variant; Trichohepatoneurodevelopmental syndrome; Whole exome sequencing.