Ruti Parvari

Weill–Marchesani syndrome (WMS) is a rare genetic inherited disorder with autosomal recessive and dominant modes of inheritance. WMS is characterized by the association of short stature, brachydactyly, joint stiffness, eye anomalies, including microspherophakia and ectopia of the lenses, and, occasionally, heart defects. We investigated the genetic cause of a unique and novel presentation of heart-developed membranes in the supra-pulmonic, supramitral, and subaortic areas, creating stenosis that recurred after their surgical resection in four patients from one extended consanguineous family. The patients also presented ocular findings consistent with Weill–Marchesani syndrome (WMS). We used whole exome sequencing (WES) to identify the causative mutation and report it as a homozygous nucleotide change c. 232T>C causing p. Tyr78His in ADAMTS10. ADAMTS10 (ADAM Metallopeptidase with Thrombospondin Type 1 Motif 10) is a member of a family of zinc-dependent extracellular matrix protease family. This is the first report of a mutation in the pro-domain of ADAMTS10. The novel variation replaces a highly evolutionary conserved tyrosine with histidine. This change may affect the secretion or function of ADAMTS10 in the extracellular matrix. The compromise in protease activity may thus cause the unique presentation of the developed membranes in the heart and their recurrence after surgery.

Familial non-medullary thyroid cancer (FNMTC) is a well-differentiated thyroid cancer (DTC) of follicular cell origin in two or more first-degree relatives. Patients typically demonstrate an autosomal dominant inheritance pattern with incomplete penetrance. While known genes and chromosomal loci account for some FNMTC, the molecular basis for most FNMTC remains elusive. To identify the variation(s) causing FNMTC in an extended consanguineous family consisting of 16 papillary thyroid carcinoma (PTC) cases, we performed whole exome sequence (WES) analysis of six family patients. We demonstrated an association of ARHGEF28, FBXW10, and SLC47A1 genes with FNMTC. The variations in these genes may affect the structures of their encoded proteins and, thus, their function. The most promising causative gene is ARHGEF28, which has high expression in the thyroid, and its protein-protein interactions (PPIs) suggest predisposition of PTC through ARHGEF28-SQSTM1-TP53 or ARHGEF28-PTCSC2-FOXE1-TP53 associations. Using DNA from a patient’s thyroid malignant tissue, we analyzed the possible cooperation of somatic variations with these genes. We revealed two somatic heterozygote variations in XRCC1 and HRAS genes known to implicate thyroid cancer. Thus, the predisposition by the germline variations and a second hit by somatic variations could lead to the progression to PTC.

Dilated cardiomyopathy (DCM) with left ventricular non-compaction (LVNC) is a primary myocardial disease leading to contractile dysfunction, progressive heart failure, and excessive risk of sudden cardiac death. Using whole-exome sequencing to investigate a possible genetic cause of DCM with LVNC in a consanguineous child, a homozygous nucleotide change c.1532G>A causing p.Arg511His in PHACTR2 was found. The missense change can affect the binding of PHACTR2 to actin by eliminating the hydrogen bonds between them. The amino acid change does not change PHACTR2 localization to the cytoplasm. The patient’s fibroblasts showed a decreased globular to fibrillary actin ratio compared to the control fibroblasts. The re-polymerization of fibrillary actin after treatment with cytochalasin D, which disrupts the actin filaments, was slower in the patient’s fibroblasts. Finally, the patient’s fibroblasts bridged a scar gap slower than the control fibroblasts because of slower and indirect movement. This is the first report of a human variation in this PHACTR family member. The knock-out mouse model presented no significant phenotype. Our data underscore the importance of PHACTR2 in regulating the monomeric actin pool, the kinetics of actin polymerization, and cell movement, emphasizing the importance of actin regulation for the normal function of the human heart.

Congenital insensitivity to pain (CIP) is a group of rare genetic disorders with a common characteristic of absent sensation to nociceptive pain. Here we present a series of six patients; three had a novel variant in the PRDM12 gene (group A), and three had a missense variant in the SCN9A gene (group B). We compared the ocular manifestations between the two groups. Records of these patients from 2009 through 2018 were reviewed. The retrieved data included demographics, genetic analysis results, ocular history and ophthalmic findings including visual acuity, corneal sensitivity, tear production, ocular surface findings, cycloplegic refraction, and fundoscopy. We found that patients with PRDM12 variant had more severe manifestations of ocular surface disease, with more prevalent corneal opacities and worse visual acuity, compared to patients with SCN9A variant.

Dedicator of cytokinesis 10 (Dock10) is a guanine nucleotide exchange factor for Cdc42 and Rac1 that regulates the JNK (c-Jun N-terminal kinase) and p38 MAPK (mitogen-activated protein kinase) signaling cascades. In this study, we characterized the roles of Dock10 in the myocardium. In vitro: we ablated Dock10 in neonatal mouse floxed Dock10 cardiomyocytes (NMCMs) and cardiofibroblasts (NMCFs) by transduction with an adenovirus expressing Cre-recombinase. In vivo, we studied mice in which the Dock10 gene was constitutively and globally deleted (Dock10 KO) and mice with cardiac myocyte-specific Dock10 KO (Dock10 CKO) at baseline and in response to two weeks of Angiotensin II (Ang II) infusion. In vitro, Dock10 ablation differentially inhibited the α-adrenergic stimulation of p38 and JNK in NMCM and NMCF, respectively. In vivo, the stimulation of both signaling pathways was markedly attenuated in the heart. The Dock10 KO mice had normal body weight and cardiac size. However, echocardiography revealed mildly reduced systolic function, and IonOptix recordings demonstrated reduced contractility and elevated diastolic calcium levels in isolated cardiomyocytes. Remarkably, Dock10 KO, but not Dock10 CKO, exaggerated the pathological response to Ang II infusion. These data suggest that Dock10 regulates cardiac stress-related signaling. Although Dock10 can regulate MAPK signaling in both cardiomyocytes and cardiofibroblasts, the inhibition of pathological cardiac remodeling is not apparently due to the Dock10 signaling in the cardiomyocyte.

Infertility affects one in six couples, half of which are caused by a male factor. Male infertility can be caused by both, qualitative and quantitative defects, leading to Oligo- astheno-terato-zoospermia (OAT; impairment in ejaculate sperm cell concentration, motility and morphology). Azoospermia defined as complete absence of sperm cells in the ejaculation. While hundreds of genes are involved in spermatogenesis the genetic etiology of men’s infertility remains incomplete.We identified a hemizygous stop gain pathogenic variation (PV) in the X-linked Germ Cell Nuclear Acidic Peptidase (GCNA), in an Azoospermic patient by exome sequencing. Assessment of the prevalence of pathogenic variations in this gene in infertile males by exome sequence data of 11 additional unrelated patients identified a probable hemizygous causative missense PV in GCNA in a severe OAT patient. Expression of GCNA in the patients’ testes biopsies and the stage of spermatogonial developmental arrest were determined by immunofluorescence and immunohistochemistry. The Azoospermic patient presented spermatogenic maturation arrest with an almost complete absence of early and late primary spermatocytes and thus the complete absence of sperm. GCNA is critical for genome integrity and its loss results in genomic instability and infertility in Drosophila, C. elegans, zebrafish, and mouse. PVs in GCNA appear to be incompatible with male fertility in humans as well: A stop-gain PV caused Azoospermia and a missense PV caused severe OAT with very low fertilization rates and no pregnancy in numerous IVF treatments.

Aldosterone synthase deficiency (ASD) is a rare potentially life‐threatening genetic disorder that usually presents during infancy due to pathogenic variants in the CYP11B2 gene. Knowledge about CYP11B2 variants in the Arab population is scarce. Here, we present and analyze five Palestinian patients and their different novel pathogenic variants. Data on clinical presentation, electrolytes, plasma renin activity, and steroid hormone levels of five patients diagnosed with ASD were summarized. Sequencing of the CYP11B2 gene exons was followed by evolutionary conservation analysis and structural modeling of the variants. All patients were from highly consanguineous Palestinian families. The patients presented at 1–4 months of age with recurrent vomiting, poor weight gain, hyponatremia, hyperkalemia, and low aldosterone levels. Genetic analysis of the CYP11B2 gene revealed three homozygous pathogenic variants: p.Ser344Profs*9, p.G452W in two patients from an extended family, and p.Q338stop. A previously described pathogenic variant was found in one patient: p.G288S. We described four different CYP11B2 gene pathogenic variants in a relatively small population. Our findings may contribute to the future early diagnosis and therapy for patients with ASD among Arab patients who present with failure to thrive and compatible electrolyte disturbances.

Duchenne muscular dystrophy (DMD) is a progressive muscular damage disorder caused by mutations in dystrophin gene. Cardiomyopathy may first be evident after 10 years of age and increases in incidence with age. We present a boy diagnosed at 18 months with a rare phenotype of DMD in association with early-onset hypertrophic cardiomyopathy (HCM). The cause of DMD is a deletion of exons 51–54 of dystrophin gene. The cause of HCM was verified by whole exome sequencing. Novel missense variations in two genes: MAP2K5 inherited from the mother and ACTN2 inherited from the father, or de novo. The combination of MAP2K5, ACTN2, and dystrophin mutations, could be causing the HCM in our patient. This is the second patient diagnosed, at relatively young age, with DMD and HCM, with novel variations in genes known to cause HCM. This study demonstrates the need for genetic diagnosis to elucidate the underlying pathology of HCM. ^* These authors contributed equally to this work. Received: 24 June 2020 Accepted: 12 September 2020 Publication Date: 19 November 2020 (online) © 2020. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Background: Oligoteratoasthenozoospermia (OTA) combines deteriorated quantity, morphology and motility of the sperm, resulting in male factor infertility.Methods: We used whole genome genotyping and exome sequencing to identify the mutation causing OTA in four men in a consanguineous Bedouin family. We expressed the normal and mutated proteins tagged with c-Myc at the carboxy termini by transfection with pCDNA3.1 plasmid constructs to evaluate the effects on protein stability in HEK293 cells and on the kinetics of actin repolymerisation in retinal pigment epithelium cells. Patients’ sperm samples were visualised by transmission electron microscopy to determine axoneme structures and were stained with fluorescent phalloidin to visualise the fibrillar (F)-actin.Results: A homozygous missense mutation in Ciliogenesis Associated TTC17 Interacting Protein (CATIP): c. T103A, p. Phe35Ile, a gene encoding a protein important in actin organisation and ciliogenesis, was identified as the causative mutation with a LOD score of 3.25. The mutation reduces the protein stability compared with the normal protein. Furthermore, overexpression of the normal protein, but not the mutated protein, inhibits repolymerisation of actin after disruption with cytochalasin D. A high percentage of spermatozoa axonemes from patients have abnormalities, as well as disturbances in the distribution of F-actin.Conclusion: This is the first report of a recessive mutation inCATIPin humans. The identified mutation may contribute to asthenozoospermia by its involvement in actin polymerisation and on the actin cytoskeleton. A mouse knockout homozygote for CATIP was reported to demonstrate male infertility as the sole phenotype.