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.

Transabdominal Embryofetoscopy for the Detection of Short Rib-polydactyly Syndrome, Type II(Majewski), in the First Trimester

Our aim was to demonstrate the potential of first-trimester embryofetoscopy for prenatal diagnosis in a continuing pregnancy. A patient at risk for giving birth to an infant with short rib-polydactyly syndrome, type II (Majewski), presented for prenatal diagnosis at 9 weeks of gestation. A 1 mm semirigid fiberoptic endoscope with an 18 gauge examination sheath and a single-chip digital camera were used for transabdominal embryofetoscopy. Transabdominal embryofetoscopy was performed at 13 weeks of gestation. Direct visualization of the fetus was achieved and no gross limb or facial abnormalities were seen. This case shows that embryofetoscopy is a useful tool for early diagnosis in high-risk patients in the first trimester for continuing pregnancies.

A Case of Saldino-Noonan Type Short Rib-Polydactyly Syndrome

Short rib-polydactyly syndrome (SRPS) is a rare type of skeletal dysplasia characterized by short limb dysplasia, thoracic hypoplasia, polydactyly and multiple visceral anomalies. It is transmitted as a autosomal recessive trait. There have been 4 classic types of SRPS, of which Saldino-Noonan type is the most common, and is characterized by very narrow thorax, short limb, postaxial polydactyly, striking metaphyseal dysplasia of tubular bones, pelvic abnormalities, hypoplasia of iliac bones, flat acetabulae, and abnormalities of urogenital, anorectal and cardiovascular system. We report a newborn infant who had typical features of Saldino-Noonan type SRPS, clinically and radiologically and had compatible autopsy findings.

Osteochondrodysplasia Pathologic study of 29 autopsy cases

Osteochondrodysplasia is a heterogeneous group of disorders appearing short limbed dwarfism. Because many of these entities are lethal and hereditary, an accurate diagnosis is mandatory. The purpose of this study is to define the clinicopathologic features and radiologic findings of osteochondrodysplasia. We reviewed 29 autopsy cases of congenital short limbed dwarfism, consisting of thanatophoric dysplasia (TD) (12 cases), osteogenesis imperfecta (OI) (12 cases), asphyxiating thoracic dysplasia (ATD) (3 cases), short-rib-polydactyly syndrome (SRPS) (1 case) and hypochondrogenesis (1 case). The gestational age ranged from 16 to 41 weeks. Of 6 fetuses that were born alive, 3 were ATD, 2 were TD and 1 was hypochondrogenesis. TD was frequently complicated by hydramnios. Of 8 cases studied chromosomally, only 1 showed chromosomal abnormality -46XY, inv 9. Intrauterine growth retardation was frequently associated with OI. Pulmonary hypoplasia was present in 23 cases (79%), including all cases of ATD, SRPS and hypochondrogenesis, 11 in TD and 7 in OI. Other associated anomalies were present in 17 cases (59%).