Verma-Naumoff syndrome: a case report / Síndrome de Verma-Naumoff: a propósito de un caso

In skeletal dysplasias, there are short rib polydactyly syndromes, which traditionally differentiate into four lethal types. This report describes a case of Type III, which presented characteristics of Types I and II. A 38-year-old woman presented fetal growth restriction at 17 weeks and 6 days, decreased amniotic fluid, enlarged and hyperechogenic kidneys, and long bones below the 3rd percentile. Three weeks later, she developed anhydramnia. The couple did not consent to the performance of an invasive test for genetic diagnosis and chose to maintain the pregnancy. At 33 weeks, due to premature labor and interactivity, a cesarean section was performed, giving birth to a female baby, who died due to respiratory failure there were no vocal cords and no trachea visible at laryngoscopy. On physical examination, he had the phenotypic characteristics of the syndrome. An X-ray showed short ribs and severe pulmonary hypoplasia. After birth, the parents chose not to carry out a genetic study or an anatomical examination. Researchers have suggested that there is an intersection of the anatomical changes of the types. This case report supports this theory.

En las displasias esqueléticas, existen síndromes de polidactilia de costillas cortas, que tradicionalmente se diferencian en cuatro tipos letales. Este reporte describe un caso del tipo III, que presentó características de los tipos I y II. Mujer de 38 años con restricción del crecimiento fetal a las 17 semanas y 6 días, líquido amniótico disminuido, riñones agrandados e hiperecogénicos y huesos largos por debajo del percentil 3. Tres semanas después, desarrolló anhidramnia. La pareja no consintió en la realización de una prueba invasiva de diagnóstico genético y optó por mantener el embarazo. A las 33 semanas, debido al parto prematuro y la interactividad, se realizó una cesárea, dando a luz a un bebé, que murió debido a una insuficiencia respiratoria: no había cuerdas vocales ni tráquea visible en la laringoscopia. Al examen físico presentaba las características fenotípicas del síndrome. Una radiografía mostró costillas cortas e hipoplasia pulmonar severa. Después del nacimiento, los padres optaron por no realizar un estudio genético ni un examen anatómico. Los investigadores han sugerido que existe una intersección de los cambios anatómicos de los tipos. Este reporte de caso apoya esta teoría.

Early prenatal diagnosis of a recurrent case of short-rib thoracic dysplasia 3 due to compound heterozygosity for variations in the DYNC2H1 gene: an "ultrasound first" approach.

Short-rib thoracic dysplasia 3 with or without polydactyly (OMIM # 613091) represents a clinical spectrum encompassing a heterogeneous group of skeletal dysplasias associated with homozygous or compound heterozygous mutations of DYNC2H1. We describe the case of a couple with two consecutive therapeutic abortions due to a diagnosis of short-rib thoracic dysplasia mutations. In the first pregnancy, the diagnosis has been made at 21 weeks. In the second one, an accurate and early ultrasound examination allowed a diagnosis at 12 weeks. DYNC2H1 mutations were confirmed in both cases. In this report, we underline the importance of an ultrasound evaluation at the end of the first trimester of pregnancy in the detection of early signs of skeletal dysplasias. An early prenatal diagnosis of a short-rib skeletal dysplasia, such as for other severe skeletal dysplasias, is critical to offer a couple the chance of a weighted, informed, and less traumatic decision about the continuation of the pregnancy.

Characterization of a novel deep-intronic variant in DYNC2H1 identified by whole-exome sequencing in a patient with a lethal form of a short-rib thoracic dysplasia type III.

Biallelic pathogenic variants in DYNC2H1 are the cause of short-rib thoracic dysplasia type III with or without polydactyly (OMIM #613091), a skeletal ciliopathy characterized by thoracic hypoplasia due to short ribs. In this report, we review the case of a patient who was admitted to the Neonatal Intensive Care Unit (NICU) of Indiana University Health (IUH) for respiratory support after experiencing respiratory distress secondary to a small, narrow chest causing restrictive lung disease. Additional phenotypic features include postaxial polydactyly, short proximal long bones, and ambiguous genitalia were noted. Exome sequencing (ES) revealed a maternally inherited likely pathogenic variant c.10322C > T p.(Leu3448Pro) in the DYNC2H1 gene. However, there was no variant found on the paternal allele. Microarray analysis to detect deletion or duplication in DYNC2H1 was normal. Therefore, there was insufficient evidence to establish a molecular diagnosis. To further explore the data and perform additional investigations, the patient was subsequently enrolled in the Undiagnosed Rare Disease Clinic (URDC) at Indiana University School of Medicine (IUSM). The investigators at the URDC performed a reanalysis of the ES raw data, which revealed a paternally inherited DYNC2H1 deep-intronic variant c.10606-14A > G predicted to create a strong cryptic acceptor splice site. Additionally, the RNA sequencing of fibroblasts demonstrated partial intron retention predicted to cause a premature stop codon and nonsense-mediated mRNA decay (NMD). Droplet digital RT-PCR (RT-ddPCR) showed a drastic reduction by 74% of DYNCH2H1 mRNA levels. As a result, the intronic variant was subsequently reclassified as likely pathogenic resulting in a definitive clinical and genetic diagnosis for this patient. Reanalysis of ES and fibroblast mRNA experiments confirmed the pathogenicity of the splicing variants to supplement critical information not revealed in original ES or CMA reports. The NICU and URDC collaboration ended the diagnostic odyssey for this family; furthermore, its importance is emphasized by the possibility of prenatally diagnosing the mother's current pregnancy.

Expanding the phenotypic spectrum of IFT81: Associated ciliopathy syndrome.

Short-rib polydactyly syndromes are a heterogeneous group of disorders characterized by narrow thorax with short ribs, polydactyly and often other visceral and skeletal malformations. To date there have only been six reported patients with homozygous and compound heterozygous variants in IFT81, causing a short-rib thoracic dysplasia, with, or without, polydactyly (SRTD19: OMIM 617895). IFT81 is a protein integral to the core of the intraflagellar transport complex B (IFT-B), which is involved in anterograde transport in the cilium. We describe the case of a male infant with compound heterozygous variants in IFT81, who presented with short long bones, a narrow thorax, polydactyly, and multiple malformations. Three novel clinical features are reported including complete situs inversus, micropenis, and rectal atresia, which have not previously been associated with variants in IFT81. We reviewed the literature and identified the most consistent clinical features associated with this rare ciliopathy syndrome. We postulate that dolichocephaly and sagittal craniosynostosis may be associated with this condition, and provide a clue to considering IFT81 as the causative gene when deciphering complex ciliopathies.

IFT52 as a Novel Candidate for Ciliopathies Involving Retinal Degeneration.

Purpose: Mutations in the intraflagellar transport protein 52 homolog (IFT52) gene are reported to interrupt ciliary function and cause short-rib thoracic dysplasia (SRTD), a specific form of skeletal ciliopathy. However, the roles of these mutations in retinal ciliopathy are inexplicit. We herein aim to study the impact of IFT52 mutations in retinopathies. Methods: A patient with syndromic ciliopathy, presenting mild SRTD (skeletal ciliopathy) and Liber congenital amaurosis (LCA; retinal ciliopathy), and nine unaffected family members were recruited. Comprehensive systemic evaluations, including ophthalmic tests, were received by the patient. Whole genome sequencing (WGS) was applied for genetic annotation. An in vitro cell system was employed to study the pathogenicity of the variant. Results: WGS identified a homozygous missense variation in IFT52, c.556A>G (p.T186A), carried by the patient but absent in both unaffected siblings. In silico analysis supported the pathogenic nature of this highly conserved variant. Structural analysis suggested that this substitution could generate a novel hydrogen bond between the mutated residue 186 and proline at residue 192, thus potentially interrupting the tertiary structure and the stability of the IFT52 protein. In vitro cellular study indicated that this mutation might disturb the stability of encoded IFT52 protein and dramatically disrupt cilia elongation in hTERT-RPE1 cells in a loss-of-function manner. Conclusions: This report expands ocular phenotypes of IFT52 mutation-caused ciliopathy to include retinal ciliopathy and demonstrates its deleterious nature in interrupting primary ciliary function. Our study hence highlights the need for screening for IFT52 mutations in LCA patients and ophthalmic reviews of patients carrying IFT52 mutations.

Prenatal diagnosis of short-rib polydactyly syndrome type III or short-rib thoracic dysplasia 3 with or without polydactyly (SRTD3) associated with compound heterozygous mutations in DYNC2H1 in a fetus.

OBJECTIVE: We present the perinatal imaging findings and molecular genetic analysis in a fetus with short-rib polydactyly syndrome (SRPS) type III or short-rib thoracic dysplasia 3 with or without polydactyly (SRTD3). CASE REPORT: A 29-year-old, primigravid woman was referred for genetic counseling at 15 weeks of gestation because of abnormal ultrasound findings of short limbs, a narrow chest and bilateral polydactyly of the hands and feet, consistent with a diagnosis of SRPS type III. Chorionic villus sampling was performed, and targeted next-generation sequencing (NGS) was applied to analyze a panel of 25 genes including CEP120, DYNC2H1, DYNC2LI1, EVC, EVC2, FGFR2, FGFR3, HOXD10, IFT122, IFT140, IFT172, IFT52, IFT80, KIAA0586, NEK1, PAPSS2, SLC26A2, SOX9, TCTEX1D2, TCTN3, TTC21B, WDR19, WDR34, WDR35 and WDR60. The NGS analysis identified novel mutations in the DYNC2H1 gene. The fetus was compound heterozygous for a missense mutation c.8077G > T (p.Asp2693Tyr) of paternal origin in DYNC2H1 and a frameshift mutation c.11741_11742delTT (p.Phe3914X) of maternal origin in DYNC2H1. The fetus had a karyotype of 46,XY, and postnatally manifested characteristic SRPS type III phenotype. CONCLUSION: Targeted NGS is useful in genetic diagnosis of fetal skeletal dysplasia and SRPS, and the information acquired is helpful in genetic counseling.

Targeted gene panel sequencing prenatally detects two novel mutations of DYNC2H1 in a fetus with increased biparietal diameter and polyhydramnios.

BACKGROUND: Genetic skeletal disorders (GSDs) are clinically and genetically heterogeneous with more than 350 genes accounting for the diversity of disease phenotypes. Prenatal diagnosis of these disorders has been challenging because of the limited but variable prenatal phenotypes, highlighting the need of a novel genetic approach. Short-rib polydactyly syndrome (SRPS) Type III is an autosomal recessive GSD characterized by extreme narrowness of the thorax, severely shortened tubular bones, polydactyly and multiple malformations. METHODS: Cytogenetic and molecular analyses using GTG-banding, single nucleotide polymorphism array and a novel GSDs targeted gene panel sequencing were performed in a 24 weeks fetus with increased biparietal diameter (BPD), short limbs, narrow thorax and polyhydramnios. RESULTS: No chromosomal abnormalities and pathogenic copy number variations (CNVs) were detected in the fetus. Two novel compound heterozygous mutations c.2992C > T and c.12836G > C in the DYNC2H1 gene were identified by targeted genes panel sequencing. A literature review was performed to delineate the prenatal phenotype of SRPS Type III. CONCLUSION: This is the first report of prenatal diagnosis of DYNC2H1 mutations causing SRPS Type III in a fetus with increased BPD associated with polyhydramnios in China. Our findings expand the mutation spectrum of DYNC2H1 in this rare disease and demonstrate that targeted gene panel capture followed by next-generation sequencing (NGS) is an efficient and cost-effective method to perform a molecular prenatal diagnosis of a rare genetic skeletal disorder.

Prenatal diagnosis and molecular genetic analysis of short rib-polydactyly syndrome type III (Verma-Naumoff) in a second-trimester fetus with a homozygous splice site mutation in intron 4 in the NEK1 gene.

OBJECTIVE: To demonstrate perinatal imaging findings and to investigate the mutation in the NEK1 gene in a fetus with type III short rib-polydactyly syndrome (SRPS) (Verma-Naumoff). CASE REPORT: A 34-year-old woman with no past history of fetal SRPS was referred to the hospital at 21 weeks of gestation because of sonographic diagnosis of short limbs in the fetus. Fetal ultrasound revealed a narrow thorax, short ribs, short limbs with marginal spurs, and postaxial hexadactyly in both the hands and feet. A diagnosis of SRPS III (Verma-Naumoff) was made. Amniocentesis was performed. The karyotype was 46,XY. Molecular genetic analysis of the amniotic fluid cells identified a homozygous splice site mutation in intron 4 (c.331-1 A > G) or IVS4-1 A > G in the NEK1 gene. The parents were heterozygous for the mutation. The pregnancy was subsequently terminated and a malformed fetus was delivered with prominent forehead, a flattened nasal bridge, a narrow and short trunk, a protuberant abdomen, bilateral postaxial polydactyly and syndactyly of the hands and feet, and micromelic limbs. No facial cleft or genital abnormality was noted. The radiograph was consistent with SRPS III. CONCLUSION: Polydactyly, micromelia, metaphyseal spurs, widened humeral metaphyses, and shortened ribs can be prominent prenatal ultrasound findings of SRPS III. The present case provides evidence for a correlation of a mutation in the NEK1 gene with SRPS III.

Short rib-polydactyly syndrome type II (Majewski): prenatal diagnosis, perinatal imaging findings and molecular analysis of the NEK1 gene.

OBJECTIVE: To demonstrate perinatal imaging findings and to investigate the mutation in the NEK1 gene in a fetus with type II short rib-polydactyly syndrome (SRPS) (Majewski). CASE REPORT: A 34-year-old woman with a past history of fetal SRPS was referred to the hospital at 16 weeks of gestation because of sonographic diagnosis of short limbs in the fetus. Fetal ultrasound revealed short ribs, short limbs, absence of tibiae, polydactyly, syndactyly and choroid plexus cysts. At 21 weeks of gestation, polycystic kidneys were found. The pregnancy was terminated, and a fetus was delivered with facial dysmorphism, a median cleft lip, a narrow chest, micromelia, aplasia of tibiae, hypoplastic nails, syndactyly and postaxial polydactyly. The karyotype was 46,XX. Molecular analysis of fetal tissues showed a paternal-origin heterozygous splice site mutation in intron 7 (c.465-1 G>A) in the NEK1 gene, but no mutations in the genes of WDR35, DYNC2H1, IFT80, EVC and EVC2. The NEK1 mutation causes an alteration of the splice acceptor site of intron 7 (IVS7-1 G>A). No second mutation was identified. CONCLUSION: Tibial aplasia, choroid plexus cysts and polycystic kidneys can be prominent prenatal ultrasound findings of type II SRPS. The present case provides evidence for a correlation of NEK1 mutation with type II SRPS.

An/micr-ophthalmia, cleft lip/palate, and short limbs: a new syndrome simulating a short rib syndrome.

We report on a male infant born at 38 weeks of gestation with hydrocephalus, right anophthalmia, left microphthalmia, cleft palate, midline cleft of lip, and microphallus. Autopsy showed pulmonary bronchial lymphangiectasia, hepatic periportal fibrosis, adrenal agenesis, ventricular septal defect, aortic stenosis, and undescended testes. The radiographic findings include short limbs and mild shortness of ribs. Karyotype with high-resolution banding was normal (46,XY). The combination of anomalies in this case could suggest a ciliopathy and may represent a new entity similar to that described by Cideciyan et al. [1].

Educational paper: ciliopathies.

Cilia are antenna-like organelles found on the surface of most cells. They transduce molecular signals and facilitate interactions between cells and their environment. Ciliary dysfunction has been shown to underlie a broad range of overlapping, clinically and genetically heterogeneous phenotypes, collectively termed ciliopathies. Literally, all organs can be affected. Frequent cilia-related manifestations are (poly)cystic kidney disease, retinal degeneration, situs inversus, cardiac defects, polydactyly, other skeletal abnormalities, and defects of the central and peripheral nervous system, occurring either isolated or as part of syndromes. Characterization of ciliopathies and the decisive role of primary cilia in signal transduction and cell division provides novel insights into tumorigenesis, mental retardation, and other common causes of morbidity and mortality, including diabetes mellitus and obesity. New technologies ("Next generation sequencing/NGS") have considerably improved genetic research and diagnostics by allowing simultaneous investigation of all disease genes at reduced costs and lower turn-around times. This is undoubtedly a result of the dynamic development in the field of human genetics and deserves increased attention in genetic counselling and the management of affected families.

Majewski osteodysplastic primordial dwarfism type II (MOPD II) syndrome previously diagnosed as Seckel syndrome: report of a novel mutation of the PCNT gene.

We report on a 3-year-old boy with prenatal onset of proportionate dwarfism, postnatal severe microcephaly, high forehead with receded hairline, sparse scalp hair, beaked nose, mild retrognathia and hypotonia diagnosed at birth as Seckel syndrome. At age 3 years, he became paralyzed due to a cerebrovascular malformation. Based on the clinical and radiological features showing evidence of skeletal dysplasia, the diagnosis was revised to Majewski osteodysplastic primordial dwarfism type II (MOPD II) syndrome. Western blot analysis of the patient's lymphoblastoid cell line lysate showed the absence of the protein pericentrin. Subsequent molecular analysis identified a novel homozygous single base insertion (c.1527_1528insA) in exon 10 of the PCNT gene, which leads to a frameshift (Treo510fs) and to premature protein truncation. PCNT mutations must be considered diagnostic of MOPD II syndrome. A possible role of pericentrin in the development of cerebral vessels is suggested.

Diagnosis of short rib polydactyly syndrome type IV (Beemer-Langer syndrome) with cystic hygroma: A case report.

Short rib polydactyly syndrome (SRPS) is a very rare congenital autosomal recessive inherited disease, classified into four subtypes. It has distinct imaging findings on prenatal sonography (US) and ancillary findings on both pre- and postnatal examinations may help classify individual cases into one of four subtypes. We report the US findings in a case of SRPS type IV (Beemer-Langer dysplasia) in a male fetus with multiple congenital anomalies, including cystic hygroma. The postnatal ultrasound, radiographic, and postmortem examinations helped to classify the SRPS as type IV. We believe this is the first documented case associating cystic hygroma and polydactyly.

Short rib polydactyly syndrome - type 2 (Majewski).

Short rib polydactyly syndromes (SRPS) are a group of inherited autosomal recessive skeletal dysplasias. It is characterized by the triad of micromelia, polydactyly and short horizontal ribs with or without visceral involvement. We report a case of SRPS-2 in a fresh stillborn and discuss the differential diagnosis.

Ellis-van Creveld syndrome.

Ellis-van Creveld syndrome (EVC) is a chondral and ectodermal dysplasia characterized by short ribs, polydactyly, growth retardation, and ectodermal and heart defects. It is a rare disease with approximately 150 cases reported worldwide. The exact prevalence is unknown, but the syndrome seems more common among the Amish community. Prenatal abnormalities (that may be detected by ultrasound examination) include narrow thorax, shortening of long bones, hexadactyly and cardiac defects. After birth, cardinal features are short stature, short ribs, polydactyly, and dysplastic fingernails and teeth. Heart defects, especially abnormalities of atrial septation, occur in about 60% of cases. Cognitive and motor development is normal. This rare condition is inherited as an autosomal recessive trait with variable expression. Mutations of the EVC1 and EVC2 genes, located in a head to head configuration on chromosome 4p16, have been identified as causative. EVC belongs to the short rib-polydactyly group (SRP) and these SRPs, especially type III (Verma-Naumoff syndrome), are discussed in the prenatal differential diagnosis. Postnatally, the essential differential diagnoses include Jeune dystrophy, McKusick-Kaufman syndrome and Weyers syndrome. The management of EVC is multidisciplinary. Management during the neonatal period is mostly symptomatic, involving treatment of the respiratory distress due to narrow chest and heart failure. Orthopedic follow-up is required to manage the bones deformities. Professional dental care should be considered for management of the oral manifestations. Prognosis is linked to the respiratory difficulties in the first months of life due to thoracic narrowness and possible heart defects. Prognosis of the final body height is difficult to predict.

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.

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.