Genetic analysis of a pedigree of DYNC2H1 gene variation-caused short rib polydactyly syndrome type Ⅲ / 中华围产医学杂志

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.

DYNC2H1 gene mutation analysis and prenatal diagnosis in two pedigrees affected with short rib-polydactyly syndrome type Ⅲ / 中华围产医学杂志

Objective:To investigate the molecular genetic etiology of two fetuses with short rib-polydactyly syndrome type Ⅲ (SRPS Ⅲ).Methods:Next-generation sequencing (NGS) was used to detect 226 known genes related to inherited skeletal dysplasia in two fetuses with SRPS Ⅲ diagnosed in the First Affiliated Hospital of Zhengzhou University in August 2015 and June 2020. Suspect pathological variants were verified in the pedigree members using Sanger sequencing. The prenatal genetic diagnosis of the high-risk fetus in pedigree one was conducted to identify the confirmed pathogenic variation.Results:The homozygous mutation of DYNC2H1 gene c.5881A>G(p.Lys1961Glu) was identified in the proband in pedigree one, and the parents were the carriers. The proband in pedigree two carried compound heterozygous mutations in the DYNC2H1 gene with c.10606C>T(p.Arg3536*) inherited from the father and c.8954T>G(p.Val2985Gly) from the mother. Autosomal recessive inheritance was confirmed in both pedigrees. Mutations of c.5881A>G(p.Lys1961Glu) and c.8954T>G(p.Val2985Gly) in the DYNC2H1 gene were likely pathogenic variants and had not been reported before. The prenatal diagnosis did not identify the DYNC2H1 gene c.5881A>G(p.Lys1961Glu) mutation in the fetus (Ⅱ-7) in pedigree one, which was confirmed by the umbilical cord blood sample after birth. Conclusion:DYNC2H1 gene mutation underlies the fetal skeletal dysplasia in the two pedigrees.

Short rib-thoracic dysplasia syndrome (type Ⅲ) caused by compound heterozygous mutation in DYNC2H1: a case report / 中华围产医学杂志

We reported one fetus who was identified with significantly short humeri and femora,bulging abdomen and narrowed chest at 22+2 weeks' gestation,which was consistent with clinical findings at birth.Genetic analysis revealed that this was a case of short-rib thoracic dysplasia syndrome (type Ⅲ) caused by compound heterozygous mutation in DYNC2H1.We summarized the features of prenatal ultrasound imaging and results of postpartum genetic analysis of this case to provide information for prenatal ultrasound diagnosis and postpartum consultation.