BACKGROUND: The protein kinase domain containing cytoplasmic (PKDCC) gene (OMIM#618821) is associated with bone development. Biallelic variants in the PKDCC gene can cause rhizomelic limb shortening with dysmorphic features.
METHODS: A fetus was found to be rhizomelic limb shortening at 16 weeks of gestation and amniocentesis was performed at 19 weeks of gestation. Genomic DNA extracted from the amniotic fluid was subjected to chromosomal microarray analysis (CMA), and Trio-total whole-exome sequencing (Trio-WES). Sanger sequencing was used to verify the candidate pathogenic variants. CMA was normal, while Trio-WES identified two compound heterozygous variants in the PKDCC gene, namely c.417_c.423delCGGCGCG insTCATGGGCTCAGTACAC(p.G140fs*35) and c.345G>A (p.W115*,379). Then the fetus was aborted and the development of its bone cells were compared with that of a normal fetus of similar gestational age by histopathological examination. Clinical findings of the fetus were shortening humerus and femur, synophrys, much hair on the side face, simian line on the right palm, etc. Histopathological examination showed that the affected fetus had increased proliferative chondrocytes, widened proliferative bands, and delayed bone mineralization.
CONCLUSIONS: We reported a prenatal case of rhizomelic shortening of limbs caused by compound heterozygous variants in the PKDCC gene, which emphasized the important role of Trio-WES for diagnosis of skeletal dysplasia in fetuses.

BACKGROUND: Frontonasal dysplasia (FND) is a rare congenital anomaly resulting from the underdevelopment of the frontonasal process, and it can be syndromic or nonsyndromic. The typical features of FND include a deformed nose and ocular hypertelorism, which are sometimes associated with cleft lip and/or palate. Only approximately 10 cases of prenatally diagnosed nonsyndromic FND have been reported in the past 30 years.
METHODS: A 33-year-old woman (G2P1) was referred to our center at 20 gestational weeks for bilateral hydrocephaly. We detected typical features of FND, including severe hypertelorism, median nasal bifidity, a minor cleft lip, and multiple limb anomalies using three-dimensional (3D) ultrasound. A hypoplastic corpus callosum, unilateral microtia, and a ventricular septal defect were also detected. Genetic testing, including karyotype analysis, copy number variation (CNV) analysis, trio-whole exome sequencing (trio-WES), and trio-whole-gene sequencing (trio-WGS), was performed; however, we did not find any de novo gene variants in the fetus as compared to the parents. Postmortem examination confirmed the prenatal diagnosis of FND.
CONCLUSIONS: The present case expands the wide phenotypic spectrum of prenatal FND patients. 3D ultrasound is a useful tool for detecting facial and limb deformities.

UNASSIGNED: VATER/VACTERL-like association is associated with adverse pregnancy outcomes. Genetic evidence of this disorder is sporadic. In this study, we aimed to provide genetic insights to improve the diagnosis of VACTERL.
UNASSIGNED: We have described a Chinese family in which four members were affected by renal defects or agenesis, anal atresia, and anovaginal fistula, which is consistent with the diagnosis of a VACTERL-like association. Pedigree and genetic analyses were conducted using genome and exome sequencing.
UNASSIGNED: Segregation analysis revealed the presence of a recessive X-linked microdeletion in two living affected individuals, harboring a 196-380 kb microdeletion on Xq27.1, which was identified by familial exome sequencing. Genome sequencing was performed on the affected male, confirming a -196 kb microdeletion in Xq27.1, which included a 28% loss of the CDR-1 gene. Four family members were included in the co-segregation analysis, and only VACTERL-like cases with microdeletions were reported in X27.1.
UNASSIGNED: These results suggest that the 196-380 kb microdeletion in Xq27.1 could be a possible cause of the VATER/VACTERL-like association. However, further genetic and functional analyses are required to confirm or rule out genetic background as the definitive cause of the VACTERL association.

Adams-Oliver syndrome is a rare inherited condition characterized by scalp defects and limb abnormalities. It is caused by variants in different genes such as ARHGAP31. Here, we used an interdisciplinary approach to study a family with lower limb anomalies. We identified a novel variant in the ARHGAP31 gene that is predicted to result in a truncated protein with a constitutively activated catalytic site due to the loss of 688 amino acids involved in the C-terminal domain, essential for protein auto-inhibition. Pathogenic variants in ARHGAP31 exon 12, leading to a premature protein termination, are associated with Adams-Oliver syndrome. Bioinformatic analysis was useful to elucidate the impact of the identified genetic variant on protein structure. To better understand the impact of the identified variant, 3D protein models were predicted for the ARHGAP31 wild type, the newly discovered variant, and other pathogenetic alterations already reported. Our study identified a novel variant probably involved in Adams-Oliver syndrome and increased the evidence on the phenotypic variability in patients affected by this syndrome, underlining the importance of translational research, including experimental and bioinformatics analyses. This strategy represents a successful model to investigate molecular mechanisms involved in syndrome occurrence.

Pathogenic variants in NOTCH1 are associated with non-syndromic congenital heart disease (CHD) and Adams-Oliver syndrome (AOS). The clinical presentation of individuals with damaging NOTCH1 variants is characterized by variable expressivity and incomplete penetrance; however, data on systematic phenotypic characterization are limited. We report the genotype and phenotype of a cohort of 33 individuals (20 females, 13 males; median age 23.4 years, range 2.5-68.3 years) from 11 families with causative NOTCH1 variants (9 inherited, 2 de novo; 9 novel), ascertained from a proband with CHD. We describe the cardiac and extracardiac anomalies identified in these 33 individuals, only four of whom met criteria for AOS. The most common CHD identified was tetralogy of Fallot, though various left- and right-sided lesions and septal defects were also present. Extracardiac anomalies identified include cutis aplasia (5/33), cutaneous vascular anomalies (7/33), vascular anomalies of the central nervous system (2/10), Poland anomaly (1/33), pulmonary hypertension (2/33), and structural brain anomalies (3/14). Identification of these findings in a cardiac proband cohort supports NOTCH1-associated CHD and NOTCH1-associated AOS lying on a phenotypic continuum. Our findings also support (1) Broad indications for NOTCH1 molecular testing (any familial CHD, simplex tetralogy of Fallot or hypoplastic left heart); (2) Cascade testing in all at-risk relatives; and (3) A thorough physical exam, in addition to cardiac, brain (structural and vascular), abdominal, and ophthalmologic imaging, in all gene-positive individuals. This information is important for guiding the medical management of these individuals, particularly given the high prevalence of NOTCH1 variants in the CHD population.

VACTERL association is diagnosed based on the non-random co-occurrence of at least 3 out of 6 congenital malformations. The prevalence is thought to be less than 1 in 10,000 to 1 in 40,000. There is no known link between VACTERL association and metopic synostosis in the literature. There were 122 operated cases of metopic synostosis at our institution from 1999 to 2023, with a 2.3:1 male-to-female ratio. The authors describe the co-occurrence of VACTERL association and metopic synostosis in 3 female patients with no identifiable genetic variants. Given that VACTERL association is a diagnosis of exclusion, other rare syndromes were considered but ultimately excluded. This suggests that the co-occurrence of VACTERL association and metopic synostosis is a potentially rare finding, and underlying pathogenic variants are yet to be identified.

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Syndactyly type V (SDTY5) is an autosomal dominant extremity malformation characterized by fusion of the fourth and fifth metacarpals. In the previous publication, we first identified a heterozygous missense mutation Q50R in homeobox domain (HD) of HOXD13 in a large Chinese family with SDTY5. In order to substantiate the pathogenicity of the variant and elucidate the underlying pathogenic mechanism causing limb malformation, transcription-activator-like effector nucleases (TALEN) was employed to generate a Hoxd13Q50R mutant mouse. The mutant mice exhibited obvious limb malformations including slight brachydactyly and partial syndactyly between digits 2-4 in the heterozygotes, and severe syndactyly, brachydactyly and polydactyly in homozygotes. Focusing on BMP2 and SHH/GREM1/AER-FGF epithelial mesenchymal (e-m) feedback, a crucial signal pathway for limb development, we found the ectopically expressed Shh, Grem1 and Fgf8 and down-regulated Bmp2 in the embryonic limb bud at E10.5 to E12.5. A transcriptome sequencing analysis was conducted on limb buds (LBs) at E11.5, revealing 31 genes that exhibited notable disparities in mRNA level between the Hoxd13Q50R homozygotes and the wild-type. These genes are known to be involved in various processes such as limb development, cell proliferation, migration, and apoptosis. Our findings indicate that the ectopic expression of Shh and Fgf8, in conjunction with the down-regulation of Bmp2, results in a failure of patterning along both the anterior-posterior and proximal-distal axes, as well as a decrease in interdigital programmed cell death (PCD). This cascade ultimately leads to the development of syndactyly and brachydactyly in heterozygous mice, and severe limb malformations in homozygous mice. These findings suggest that abnormal expression of SHH, FGF8, and BMP2 induced by HOXD13Q50R may be responsible for the manifestation of human SDTY5.

BACKGROUND The VACTEREL association is an acronym that includes vertebral malformations (V), anal atresia (A), cardiac defects (C), tracheoesophageal fistula (TE), renal defects (R), and limb malformations (L). The aortic arch is the section between the ascending aorta and the descending aorta, where some variants have been described, such as the right aortic arch and bovine aortic arch, among others. A rare presentation in the Natsis classification is the \"type X\" where a bovine aortic arch and anomalous origin of the left vertebral artery are present. Several structural cardiac malformations have been described in the VACTEREL association. Still, there is no bovine arch or an anomalous left vertebral artery. CASE REPORT Our patient was a 3-year-old boy with a diagnosis of VACTEREL association (type III esophageal atresia, congenital hip dislocation, scoliosis, bilateral clubfoot, and grade IV biliary ureteral reflux). Echocardiographic findings showed changes in the aortic arch, and angiotomography and magnetic resonance angiography showed a bovine aortic arch and an anomalous left vertebral artery. At the time of diagnosis, there were no clinical manifestations or complications due to the anomalous origin of the left vertebral artery. CONCLUSIONS This is the first description of a bovine type X arch according to the Natsis classification in a VACTEREL association. In general, knowledge of the anatomical variants of the aortic arch and the origin and course of the vertebral arteries is of great clinical and interventional importance, mainly because of the risk of cerebral ischemia.

Autosomal recessive ROR2-Robinow syndrome is caused by pathogenic variants in the ROR2 gene. Fetal ultrasound done on our patient at 24 + 3/7 weeks gestation showed macrocephaly, brachycephaly, flat face, prominent forehead, mild frontal bossing, lower thoracic hemivertebrae, digital abnormalities and micropenis. Fetal trio whole exome sequencing done on amniocytes showed two pathogenic compound heterozygous variants in the ROR2 gene, c.1324 C > T; p.(Arg442*) maternally inherited and c.1366dup; p.(Leu456Profs*3) apparently de novo. c.1324 C > T; p.(Arg442*) is a nonsense variant resulting in protein truncation reported to be associated with RRS3. c.1366dup; p.(Leu456Profs*3) is a frameshift variant predicted to result in protein truncation reported to segregate with the disease in multiple affected individuals from a single large family with distal symphalangism of the fourth finger. Fetal autopsy following pregnancy termination showed a large head with low-set ears, facial abnormalities, mesomelic bone shortening, hemivertebra, fused S3 and S4 vertebral bodies, several fused rib heads and short penis with buried shaft.