Mesomelic Limb Shortening Research Articles

Mesomelia-synostoses syndrome: contiguous deletion syndrome, SULF1 haploinsufficiency or enhancer adoption?

BackgroundMesomelia-Synostoses Syndrome (MSS)(OMIM 600,383) is a rare autosomal dominant disorder characterized by mesomelic limb shortening, acral synostoses and multiple congenital malformations which is described as a contiguous deletion syndrome involving the two genes SULF1 and SLCO5A1. The study of apparently balanced chromosomal rearrangements (BCRs) is a cytogenetic strategy used to identify candidate genes associated with Mendelian diseases or abnormal phenotypes. With the improved development of genomic technologies, new methods refine this search, allowing better delineation of breakpoints as well as more accurate genotype-phenotype correlation.Case presentationWe present a boy with a global development deficit, delayed speech development and an ASD (Asperger) family history, with an apparently balanced “de novo” reciprocal translocation [t(1;8)(p32.2;q13)dn]. The cytogenetic molecular study identified a likely pathogenic deletion of 21 kb in the 15q12 region, while mate pair sequencing identified gene-truncations at both the 1p32.2 and 8q13 translocation breakpoints.ConclusionsThe identification of a pathogenic alteration on 15q12 involving GABRA5 was likely the main cause of the ASD-phenotype. Importantly, the chr8 translocation breakpoint truncating SLCO5A1 exclude SLCO5A1 as a candidate for MSS, leaving SULF1 as the primary candidate. However, the deletions observed in MSS remove a topological associated domain (TAD) boundary separating SULF1 and SLCO5A1. Hence, Mesomelia-Synostoses syndrome is either caused by haploinsufficiency of SULF1 or ectopic enhancer effects where skeletal/chrondrogenic SULF1 enhancers drive excopic expression of developmental genes in adjacent TADs including PRDM14, NCOA2 and/or EYA1.

Phenotypic and mutational spectrum of ROR2-related Robinow syndrome.

Robinow syndrome is characterized by a triad of craniofacial dysmorphisms, disproportionate-limb short stature, and genital hypoplasia. A significant degree of phenotypic variability seems to correlate with different genes/loci. Disturbances of the noncanonical WNT-pathway have been identified as the main cause of the syndrome. Biallelic variants in ROR2 cause an autosomal recessive form of the syndrome with distinctive skeletal findings. Twenty-two patients with a clinical diagnosis of autosomal recessive Robinow syndrome were screened for variants in ROR2 using multiple molecular approaches. We identified 25 putatively pathogenic ROR2 variants, 16novel, including single nucleotide variants and exonic deletions. Detailed phenotypic analyses revealed that all subjects presented with a prominent forehead, hypertelorism, short nose, abnormality of the nasal tip, brachydactyly, mesomelic limb shortening, short stature, and genital hypoplasia in male patients. A total of 19 clinical features were present in more than 75% of the subjects, thus pointing to an overall uniformity of the phenotype. Disease-causing variants in ROR2, contribute to a clinically recognizable autosomal recessive trait phenotype with multiple skeletal defects. A comprehensive quantitative clinical evaluation of this cohort delineated the phenotypic spectrum of ROR2-related Robinow syndrome. The identification of exonic deletion variant alleles further supports the contention of a loss-of-function mechanism in the etiology of the syndrome.

Craniofacial phenotypes associated with Robinow syndrome.

Robinow syndrome is characterized by mesomelic limb shortening, hemivertebrae, and genital hypoplasia. Due to low prevalence and considerable phenotypic variability, it has been challenging to definitively characterize features of Robinow syndrome. While craniofacial abnormalities associated with Robinow syndrome have been broadly described, there is a lack of detailed descriptions of genotype-specific phenotypic craniofacial features. Patients with Robinow syndrome were invited for a multidisciplinary evaluation conducted by specialist physicians at our institution. A focused assessment of the craniofacial manifestations was performed by a single expert examiner using clinical examination and standard photographic images. A total of 13 patients with clinical and molecular diagnoses consistent with either dominant Robinow syndrome (DRS) or recessive Robinow syndrome (RRS) were evaluated. On craniofacial examination, gingival hyperplasia was nearly ubiquitous in all patients. Orbital hypertelorism, a short nose with anteverted and flared nares, a triangular mouth with a long philtrum, cleft palate, macrocephaly, and frontal bossing were not observed in all individuals but affected individuals with both DRS and RRS. Other anomalies were more selective in their distribution in this patient cohort. We present a comprehensive analysis of the craniofacial findings in patients with Robinow Syndrome, describing associated morphological features and correlating phenotypic manifestations to underlying genotype in a manner relevant for early recognition and focused evaluation of these patients.

Robinow Syndrome : an anesthetic challenge and review of literature

Robinow Syndrome is characterized by the presence of mesomelic limb shortening, midfacial hypoplasia, hemivertebrae and genital hypoplasia. Multi- organ involvement including cardiac, renal, vertebral dysfunctions have been described.We here report successful anaesthetic management of 1year old boy posted for ophthalmic procedure.

DVL3 Alleles Resulting in a −1 Frameshift of the Last Exon Mediate Autosomal-Dominant Robinow Syndrome

Robinow syndrome is a rare congenital disorder characterized by mesomelic limb shortening, genital hypoplasia, and distinctive facial features. Recent reports have identified, in individuals with dominant Robinow syndrome, a specific type of variant characterized by being uniformly located in the penultimate exon of DVL1 and resulting in a -1 frameshift allele with a premature termination codon that escapes nonsense-mediated decay. Here, we studied a cohort of individuals who had been clinically diagnosed with Robinow syndrome but who had not received a molecular diagnosis from variant studies of DVL1, WNT5A, and ROR2. Because of the uniform location of frameshift variants in DVL1-mediated Robinow syndrome and the functional redundancy of DVL1, DVL2, and DVL3, we elected to pursue direct Sanger sequencing of the penultimate exon of DVL1 and its paralogs DVL2 and DVL3 to search for potential disease-associated variants. Remarkably, targeted sequencing identified five unrelated individuals harboring heterozygous, de novo frameshift variants in DVL3, including two splice acceptor mutations and three 1 bp deletions. Similar to the variants observed in DVL1-mediated Robinow syndrome, all variants in DVL3 result in a -1 frameshift, indicating that these highly specific alterations might be a common cause of dominant Robinow syndrome. Here, we review the current knowledge of these peculiar variant alleles in DVL1- and DVL3-mediated Robinow syndrome and further elucidate the phenotypic features present in subjects with DVL1 and DVL3 frameshift mutations.

DVL1 Frameshift Mutations Clustering in the Penultimate Exon Cause Autosomal-Dominant Robinow Syndrome

Robinow syndrome is a genetically heterogeneous disorder characterized by mesomelic limb shortening, genital hypoplasia, and distinctive facial features and for which both autosomal-recessive and autosomal-dominant inheritance patterns have been described. Causative variants in the non-canonical signaling gene WNT5A underlie a subset of autosomal-dominant Robinow syndrome (DRS) cases, but most individuals with DRS remain without a molecular diagnosis. We performed whole-exome sequencing in four unrelated DRS-affected individuals without coding mutations in WNT5A and found heterozygous DVL1 exon 14 mutations in three of them. Targeted Sanger sequencing in additional subjects with DRS uncovered DVL1 exon 14 mutations in five individuals, including a pair of monozygotic twins. In total, six distinct frameshift mutations were found in eight subjects, and all were heterozygous truncating variants within the penultimate exon of DVL1. In five families in which samples from unaffected parents were available, the variants were demonstrated to represent de novo mutations. All variant alleles are predicted to result in a premature termination codon within the last exon, escape nonsense-mediated decay (NMD), and most likely generate a C-terminally truncated protein with a distinct -1 reading-frame terminus. Study of the transcripts extracted from affected subjects' leukocytes confirmed expression of both wild-type and variant alleles, supporting the hypothesis that mutant mRNA escapes NMD. Genomic variants identified in our study suggest that truncation of the C-terminal domain of DVL1, a protein hypothesized to have a downstream role in the Wnt-5a non-canonical pathway, is a common cause of DRS.

Majewski Syndrome, Short Rib Polydactyly Syndrome (SRPS) Type II - A Rare Case Report, with Review of Literature

Short Rib Polydactyly Syndrome (SRPS) type II also known as Majewski syndrome, is the rarest of the four subtypes of SRPS which is a rare inherited skeletal dysplasia. We report a case of Majewski syndrome in a neonate with brief review of literature. A 24 years old primigravida, with history of second degree consanguineous marriage underwent a Prenatal USG which revealed anhydramnios, bilateral enlarged kidneys, extremely narrow thorax and bilateral short limbs with polydactyly. Based on these findings a probable diagnosis of lethal skeletal dysplasia was made and termination of pregnancy advised. Refusing termination the mother delivered a male foetus at 30 weeks with severe respiratory distress and gross anomalies. The foetus succumbed to respiratory failure inspite of resuscitation. Gross findings were a male Case Study Andola et al.; BJMMR, 9(12): 1-8, 2015; Article no.BJMMR.18367 2 foetus with enlarged head, hydropic face, hypertelorism, short nose, depressed nasal bridge, pseudo cleft lip, cleft palate, low set posterior rotated ears, cystic hygroma, micrognathia, short and narrow chest, all the limbs showed mesomelic limb shortening, postaxial polydactyly, syndactyly and brachydactyly. Postnatal X-ray, CT scan and USG confirmed the above mentioned features and additional findings were extremely short horizontal ribs and disproportionately shortened ovoid tibia. Autopsy revealed a bell shaped thorax, small hypoplastic lungs, bilateral enlarged kidneys, atrial septal defect, hypoplastic epiglottis and larynx and short small intestine. Microscopic findings of pulmonary hypoplasia, renal cystic dysplasia, hepatic fibrosis and markedly retarded endochondral ossification correlate with the clinical, radiological and pathological findings of Short Rib Polydactyly Syndrome Type II -Majewski Syndrome.

De novo WNT5A‐associated autosomal dominant Robinow syndrome suggests specificity of genotype and phenotype

Robinow Syndrome (RS), a rare skeletal dysplasia syndrome, is characterized by dysmorphic features resembling a fetal face, mesomelic limb shortening, hypoplastic external genitalia in males, and renal and vertebral anomalies. Both autosomal dominant and autosomal recessive patterns of inheritance have been reported. Since the description of autosomal dominant Robinow Syndrome (ADRS; OMIM 180700) in 1969 by Meinhard Robinow and colleagues, the molecular etiology remained elusive until only recently. WNT5A was proposed to be the candidate gene for ADRS, as mutations were found in two affected families, one of those being the originally described index family. We report three families with RS caused by novel heterozygous WNT5A mutations, which were confirmed in the first family by whole exome sequencing, and in all by Sanger sequencing. To our knowledge, this is the largest number of published families with ADRS in whom a WNT5A mutation was identified. Families 1 and 2 are the first cases showing de novo inheritance in the affected family members and thus strengthen the evidence for WNT5A as the causative gene in ADRS. Finally, we propose WNT5A mutation specificity in ADRS, which may affect interactions with other proteins in the Wnt pathway.

The First Report of Robinow Syndrome in Iran and Literature Review

Introduction: Robinow syndrome (RS) is an infrequent genetic condition that is characterized by a dysmorphic face, dental anomaly, short stature, mesomelic limb shortening, hand and foot anomalies, and hypoplastic genitalia. The Robinow syndrome has been reported from the Arab countries and other Asian countries, but has not been reported in Iranian population so far. Case Presentation: A new born (one day old) infant that had the signs of Robinow syndrome. Discussion: We describe an Iranian new born infant with Robinow syndrome signs in order to improve the science and epidemiology related to this disorder.

Prenatal diagnosis of robinow syndrome: A case report

Robinow syndrome, also known as fetal face syndrome, is a rare genetically heterogeneous condition characterized mainly by mesomelic limb shortening, facial malformations, and genital abnormalities. This report describes the sonographic findings in a case of autosomal-dominant Robinow syndrome diagnosed at 23.1 weeks' gestation, in a patient with no history of affected relatives. Here we describe the sonographic characteristics of this syndrome from the diagnosis until birth. The prenatal and postnatal findings, the differential diagnosis, and the prognosis of patients with this syndrome are discussed. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound, 42:297-300, 2014.

Identification of a novel causative mutation in the ROR2 gene in a Lebanese family with a mild form of recessive Robinow syndrome

Autosomal recessive Robinow syndrome (OMIM 268310) is a condition caused by mutations in the ROR2 gene, the receptor tyrosine kinase-like orphan receptor 2. The main characteristic features are: a face resembling that of a fetus, cleft lip and palate, mesomelic limb shortening, a micropenis in males, hydronephrosis or urinary tract infections, and skeletal and vertebral anomalies. This study reports two sisters from a consanguineous Lebanese family with an autosomal recessive Robinow syndrome. Both presented with short stature, dysmorphic facial features, and mild bone abnormalities. One of the affected girls had a malformation of her right hand: a mesoaxial polydactyly combined with a syndactyly of the 3rd and 4th fingers, and a short right 3rd metacarpal bone. Molecular analysis of the ROR2 gene revealed the presence of a previously undescribed missense mutation: p.R272C (c.814C>T), in the cysteine-rich domain of the protein. These patients are compared with other cases, and a phenotype–genotype correlation is discussed.

Identification of a Gypsy SHOX mutation (p.A170P) in Léri-Weill dyschondrosteosis and Langer mesomelic dysplasia

We report the clinical and molecular characteristics of 12 Spanish families with multiple members affected with Léri-Weill dyschondrosteosis (LWD) or Langer mesomelic dysplasia (LMD), who present the SHOX (short stature homeobox gene) mutation p.A170P (c.508G>C) in heterozygosity or homozygosity, respectively. In all studied families, the A170P mutation co-segregated with the fully penetrant phenotype of mesomelic limb shortening and Madelung deformity. A shared haplotype around SHOX was observed by microsatellite analysis, confirming the presence of a common ancestor, probably of Gypsy origin, as 11 of the families were of this ethnic group. Mutation screening in 359 Eastern-European Gypsies failed to identify any carriers. For the first time, we have shown SHOX expression in the human growth plate of a 22-week LMD fetus, homozygous for the A170P mutation. Although the mutant SHOX protein was expressed in all zones of the growth plate, the chondrocyte columns in the proliferative zone were disorganized with the chondrocytes occurring in smaller columnal clusters. We have also identified a novel mutation at the same residue, c. 509C>A (p.A170D), in two unrelated Spanish LWD families, which similar to A170P mutation impedes nuclear localization of SHOX. In conclusion, we have identified A170P as the first frequent SHOX mutation in Gypsy LWD and LMD individuals.

Functional Analysis of Conserved Non-Coding Regions Around the Short Stature hox Gene (shox) in Whole Zebrafish Embryos

BackgroundMutations in the SHOX gene are responsible for Leri-Weill Dyschondrosteosis, a disorder characterised by mesomelic limb shortening. Recent investigations into regulatory elements surrounding SHOX have shown that deletions of conserved non-coding elements (CNEs) downstream of the SHOX gene produce a phenotype indistinguishable from Leri-Weill Dyschondrosteosis. As this gene is not found in rodents, we used zebrafish as a model to characterise the expression pattern of the shox gene across the whole embryo and characterise the enhancer domains of different CNEs associated with this gene.Methodology/Principal FindingsExpression of the shox gene in zebrafish was identified using in situ hybridization, with embryos showing expression in the blood, putative heart, hatching gland, brain pharyngeal arch, olfactory epithelium, and fin bud apical ectodermal ridge. By identifying sequences showing 65% identity over at least 40 nucleotides between Fugu, human, dog and opossum we uncovered 35 CNEs around the shox gene. These CNEs were compared with CNEs previously discovered by Sabherwal et al., resulting in the identification of smaller more deeply conserved sub-sequence. Sabherwal et al.'s CNEs were assayed for regulatory function in whole zebrafish embryos resulting in the identification of additional tissues under the regulatory control of these CNEs.Conclusion/SignificanceOur results using whole zebrafish embryos have provided a more comprehensive picture of the expression pattern of the shox gene, and a better understanding of its regulation via deeply conserved noncoding elements. In particular, we identify additional tissues under the regulatory control of previously identified SHOX CNEs. We also demonstrate the importance of these CNEs in evolution by identifying duplicated shox CNEs and more deeply conserved sub-sequences within already identified CNEs.

New lethal skeletal dysplasia with Dandy–Walker malformation, congenital heart defects, abnormal thumbs, hypoplastic genitalia, and distinctive facies

We report on two sibs with a lethal form of bone dysplasia with distinctive skeletal findings including rhizomelic and mesomelic limb shortening, hooked clavicles, dumbbell femurs, and absence of talus and calcaneus ossification. Other clinical features include Dandy-Walker malformation, congenital heart defects, joint contractures, genital hypoplasia, and distinctive facial features. These sibs appear to have a previously undescribed skeletal dysplasia, which is most likely inherited in an autosomal recessive fashion.

Mesomelia-Synostoses Syndrome Results from Deletion of SULF1 and SLCO5A1 Genes at 8q13

Mesomelia-synostoses syndrome (MSS) or mesomelic dysplasia with acral synostoses Verloes-David-Pfeiffer type is a rare autosomal-dominant disorder characterized by mesomelic limb shortening, acral synostoses, and multiple congenital malformations. So far, five patients in four unrelated families have been reported worldwide with MMS. By using whole-genome oligonucleotide array CGH, we have identified an interstitial deletion at 8q13 in all patients. The deletions vary from 582 Kb to 738 Kb in size, but invariably encompass only two genes: SULF1, encoding the heparan sulfate 6-O-endosulfatase 1, and SLCO5A1, encoding the solute carrier organic anion transporter family member 5A1. SULF1 acts as a regulator of numerous growth factors in skeletal embryonic development whereas the function of SLCO5A1 is yet unknown. Breakpoint sequence analyses performed in two families showed nonrecurrent deletions. Real-time quantitative RT-PCR analysis showed the highest levels of SULF1 transcripts in human osteoblasts and cartilage whereas SLCO5A1 was highly expressed in human fetal and adult brain and heart. Our results strongly suggest that haploinsufficiency of SULF1 contributes to this mesomelic chondrodysplasia, highlighting the critical role of endosulfatase in human skeletal development. Codeletion of SULF1 and SLCO5A1--which does not result from a low-copy repeats (LCRs)-mediated recombination event in at least two families--was found in all patients, so we suggest that haploinsufficiency of SULF1 combined with haploinsufficiency of SLCO5A1 (or the altered expression of a neighboring gene through position effect) could be necessary in the pathogenesis of MSS.

Identification of the first de novo PAR1 deletion downstream of SHOX in an individual diagnosed with Léri–Weill dyschondrosteosis (LWD)

Léri–Weill dyschondrosteosis (LWD, MIM 127300), is a dominantly inherited skeletal dysplasia with disproportionate short stature, mesomelic limb shortening, and the characteristic Madelung deformity. Two regions of the pseudoautosomal region 1 (PAR1) have been shown to be involved in LWD, SHOX (short-stature homeobox-containing gene) and the downstream enhancer region. We report our genetic findings of a young girl clinically diagnosed with LWD. We analyzed the proband and her family using MLPA and microsatellite analysis. We identified a deletion, 726–866 kb in size, of the downstream SHOX enhancer region in the proband. Neither parent carried the deletion. Microsatellite analysis showed that the deleted allele was of paternal origin. The mutation is more likely to have arisen from a de novo event but paternal gonadal mosaicism cannot be excluded. In conclusion, we report the clinical and molecular details of the first case of a de novo deletion of the downstream PAR1 region in an LWD individual. De novo deletions of SHOX and the downstream enhancer region must be therefore considered in cases of isolated LWD.

Clinical and radiographic delineation of odontochondrodysplasia

The association of dentinogenesis imperfecta (DI) with a distinct form of chondrodysplasia in a boy was reported by Goldblatt et al. [1991; Am J Med Genet 39:170-172] and has been given the name of Goldblatt syndrome or odontochondrodysplasia (ODCD; OMIM#184260). Since the original description, only four further individuals have been reported (one sib pair and two unrelated cases). We report on an additional six individuals, including a second sib pair (brother and sister), with clinical and radiographic features that cluster and thus confirm the nosologic status of this entity. The main radiographic features are congenital platyspondyly with coronal clefts, severe metaphyseal changes particularly of the hands, wrists, and knees, mesomelic limb shortening, and coxa valga. The main physical signs are short stature, joint laxity, narrow chest, scoliosis, and DI. This combination of clinical and radiographic findings allows clear recognition of this syndrome in early childhood. Of note, the signs that are present in the newborn period are not entirely specific and the differential diagnosis includes spondylometaphyseal dysplasia (SMD) Sedaghatian type or platyspondylic lethal dysplasia (PSLD) Torrance type. The occurrence of two sib pairs in a group of only 11 patients suggests an autosomal recessive inheritance pattern. Overmodification of cartilage-extracted collagen 2 has been reported in two sibs, but mutation analysis of COL2A1 as well as of COMP, FGFR3, RMRP, and SBDS in one or more patients have given negative results, and the molecular etiology is as yet unknown.

New clinical findings in the Richieri-Costa/Pereira type of acrofacial dysostosis

The Richieri-Costa/Pereira form of acrofacial dysostosis is an autosomal-recessive condition characterized by short stature, Pierre-Robin sequence, preaxial and postaxial abnormalities in hands, congenital talipes, cleft mandible and malformations of the larynx. We report female infant presenting with severe micrognathia, a hypoplasic clavicle, median mandible cleft, bilateral hand abnormalities and talipes, laryngeal malformations, hip subluxation with acetabular dysplasia and mesomelic shortening of limbs. A few reported patients have clavicular hyploplasia but hip subluxation with acetabular dysplasia and mesomelic shortening of limbs have not been described.

Clinical characterization of autosomal dominant and recessive variants of Robinow syndrome

Robinow syndrome is a genetically heterogeneous condition characterized by mesomelic limb shortening associated with facial and genital anomalies that can be inherited in an autosomal dominant or recessive mode. We characterized these two variants clinically, with the aim of establishing clinical criteria to enhance the differential diagnosis between them or other similar conditions. The frequencies of clinical signs considered important for the discrimination of the dominant or recessive variants were estimated in a sample consisting of 38 patients personally examined by the authors and of 50 affected subjects from the literature. Using the presence of rib fusions as diagnostic of the recessive variant, and also based on the inheritance pattern in familial cases, we classified 37 patients as having the recessive form and other 51 as having the dominant form. The clinical signs present in more than 75% of patients with either form, and therefore the most important for the characterization of this syndrome were hypertelorism, nasal features (large nasal bridge, short upturned nose, and anteverted nares), midface hypoplasia, mesomelic limb shortening, brachydactyly, clinodactyly, micropenis, and short stature. Hemivertebrae and scoliosis were present in more than 75% of patients with the recessive form, but in less than 25% of patients with the dominant form. Umbilical hernia (32.3%) and supernumerary teeth (10.3%) were found exclusively in patients with the dominant form.

Twin pregnancy with Roberts syndrome in one fetus and trisomy 18 in the other

We report a case of a 26-year-old multigravida pregnant woman with a history of 3 stillbirths with hydrops fetalis who presented with 17 weeks menstrual age. Sonographic examination revealed twin gestation. Twin 1 showed subcutaneous edema, pleural effusion, and mesomelic limb shortening, suggestive of lethal skeletal dysplasia (Roberts syndrome). Twin 2 corresponded to 17 weeks menstrual age with no major malformations. Karyotyping of the fetuses showed normal karyotype in twin 1 and trisomy 18 in twin 2. Fetal autopsy confirmed the sonographic findings. The occurrence of trisomy 18 in the fetus may be due to chance, but it raises the possibility that the heterozygotes of Roberts syndrome may be at higher risk of nondisjunction and aneuploidy in the fetus. Furthermore, this case illustrates that karyotyping of both fetuses is warranted when 1 of the twins is found to have major malformations.