OBJECTIVE: To explore the clinical phenotype and genetic basis for a Chinese pedigree affected with Oral-facial-digital syndrome type I (OFD1). METHODS: A pedigree with OFD1 who presented at Hebei General Hospital on March 17, 2021 was selected as the subject. Clinical data of the child was collected. Trio-whole exome sequencing (trio-WES) was carried out for the proband and members of her pedigree, and candidate variant was verified by Sanger sequencing. RESULTS: The proband has featured hypotelorism, broad nasal root, flat nasal tip, lobulated tongue, tongue neoplasia, camptodactyly of left fifth finger, syndactyly of right fourth and fifth fingers, and delayed intellectual and language development. Trio-WES revealed that the proband and her daughter, sister and mother have harbored a heterozygous c.224A>G (p.Asn75Ser) variant of the OFD1 gene. The same variant was not found among healthy members from her pedigree. CONCLUSION The c.224A>G (p.Asn75Ser) variant probably underlay the OFD1 in this pedigree. Above discovery has enriched the spectrum of OFD1 gene variants.
Humans ; Female ; Pedigree ; Orofaciodigital Syndromes/genetics* ; East Asian People ; Phenotype ; Heterozygote ; Mutation ; China

This paper reported the genetic analysis of a pedigree in which three affected fetuses with short limbs were revealed by first-trimester ultrasonography in three consecutive pregnancies. Tissues of the second aborted fetus were collected and analyzed by chromosome karyotype analysis and whole exome sequencing. The results indicated compound heterozygous mutations of EX64-EX83 Del and c.8190G>T in the DYNC2H1 gene. Real-time fluorescence quantitative polymerase chain reaction and Sanger sequencing further confirmed that the two variants were inherited from the father and the mother with normal phenotypes, respectively. EX64-EX83 Del was a likely pathogenic variant and c.8190G>T was a variant of uncertain significance. Based on the above results and the medical history, it was highly suspected that the fetus had autosomal recessive short rib polydactyly syndrome type Ⅲ caused by compound heterozygous variants. Real-time fluorescent quantitative polymerase chain reaction and Sanger sequencing results of the third aborted fetus were consistent with the second fetus. Given the same phenotypes of fetuses in the second and third pregnancy, it was strongly suggested that the heterozygous variations of EX64-EX83 Del and c.8190G>T in the DYNC2H1 gene were the pathogenic variants in this pedigree.