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Townes–Brocks syndrome (TBS) is a rare syndrome characterized by triad of anal, ear, and thumb anomalies. Further malformations/anomalies include congenital heart diseases, foot malformations, sensorineural and/or conductive hearing impairment, genitourinary malformations, and anomalies of eye and nervous system. Definitive diagnosis for TBS is confirmed by molecular analysis for mutations in the SALL1 gene. Only one known case of TBS with absent pulmonary valve syndrome (APVS) has been previously described to our knowledge. Here, we report a newborn diagnosed with TBS with APVS and tetralogy of Fallot (TOF) who was found to carry the most common pathogenic SALL1 gene mutation c.826C > T (p.R276X), with its surgical repair and postoperative follow-up. To our knowledge, this is the first genotyped case of TBS from Turkey to date. TBS should be suspected in the presence of ear, anal, and thumb malformations in a neonate. If a patient with TBS and TOF-APVS needs preoperative ventilation within the first months of life, this implies prolonged postoperative intubation and increased risk of mortality.

Townes–Brocks syndrome (TBS) is a rare syndrome characterized by triad of anal, ear, and thumb anomalies. Further malformations/anomalies include congenital heart diseases, foot malformations, sensorineural and/or conductive hearing impairment, genitourinary malformations, and anomalies of eye and nervous system. Definitive diagnosis for TBS is confirmed by molecular analysis for mutations in the SALL1 gene. Only one known case of TBS with absent pulmonary valve syndrome (APVS) has been previously described to our knowledge. Here, we report a newborn diagnosed with TBS with APVS and tetralogy of Fallot (TOF) who was found to carry the most common pathogenic SALL1 gene mutation c.826C > T (p.R276X), with its surgical repair and postoperative follow-up. To our knowledge, this is the first genotyped case of TBS from Turkey to date. TBS should be suspected in the presence of ear, anal, and thumb malformations in a neonate. If a patient with TBS and TOF-APVS needs preoperative ventilation within the first months of life, this implies prolonged postoperative intubation and increased risk of mortality. https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0041-1740371

Rothmund–Thomson syndrome (RTS) is a rare autosomal recessive disorder caused by mutations in RECQL4 and has characteristic clinical features. We report two unrelated phenotypically diverse patients (cases 1 and 2) with RTS having novel variants in RECQL4 gene. Case-1 was evaluated for poor growth and recurrent fractures and skin lesions. Case-2 presented at 4 months with failure to thrive and radial ray defect and developed poikilodermatous skin lesions after infancy. Both cases were confirmed to have homozygous pathogenic variants in RECQL4. Both patients have normal intellect and are on supportive therapy. The presence of characteristic poikiloderma lesions with specific distribution and skeletal anomalies in a patient with proportionate short stature is a clue toward the diagnosis of RTS.

A 3-year-old boy presented with acute corneal hydrops on the left eye and spontaneous corneal rupture on the right eye. A diagnosis of brittle cornea syndrome was confirmed by molecular analysis. A novel mutation, the homozygous variant c.17T>G, p.V6G, was found in the gene for PR-domain-containing protein 5 (PRDM5) in exon 1. Brittle cornea syndrome is a rare connective tissue disease with typical ocular, auditory, musculoskeletal, and cutaneous disorders. Almost all patients suffer from declined vision due to corneal scarring, thinning, and rupture. The most common ophthalmologic findings include keratoconus, progressive central corneal thinning, high myopia, irregular astigmatism, retinal detachment, and high risk for spontaneous corneal or scleral rupture. In addition to describing the case with a novel mutation here we review the current literature on brittle cornea syndrome pathogenesis, clinical findings, and therapy.

Paroxysmal kinesigenic dyskinesia (PKD) (MIM 128200) is a rare paroxysmal movement disorder that occurs at an estimated prevalence of 1:150,000 individuals. 1 Onset is most commonly in childhood or adolescence, with sporadic and familial cases being reported. 2,3 PKD is characterized by short and frequent episodes of dystonic or choreiform movements that are precipitated by sudden voluntary movements or startle. Classic clinical criteria for PKD therefore include an identifiable kinesigenic trigger, short duration of attacks, no loss of consciousness or pain during attacks, normal interictal neurologic examination results, the exclusion of other organic diseases, onset between 1 and 20 years of age (if no family history), and a response to treatment with anticonvulsants (sodium channel blockers). 3 Genetically, most cases

Introduction The prevalence of neural tube defects worldwide is 1 – 2 per 1000 neonates. Neural tube defects result from a disturbance of neurulation in the 3rd or 4th week of development and thus represent the earliest manifestation of organ malformation. Neural tube defects (NTD) are classified into cranial dysraphism leading to anencephaly or meningoencephalocele and spinal dysraphism with or without meningomyelocele. In isolated form they have multifactorial causes, and the empirical risk of recurrence in Central Europe is 2%. As associated malformations they tend to occur sporadically, and in monogenic syndromes they follow Mendelian inheritance patterns with a high risk of recurrence. Patients Autopsies were performed on 68 fetuses following a prenatal diagnosis of NTD and induced abortion. Results The incidence of NTDs in our autopsied fetuses was 8% and 11% in fetuses with malformations. The percentage of fetuses with anencephaly, encephalocele or spina bifida was 24, 18, and 60%*, respectively. Analysis of the sex distribution showed a female preponderance in cranial dysraphisms but the sex distribution of spina bifida cases was equal. The extent and localization of NTDs varied, with lumbosacral cases clearly predominating. The proportion of isolated, associated and syndromic neural tube defects was 56, 23.5 and 20.6% respectively. In the majority of syndromes, the neural tube defect represented a not previously observed syndromic feature. Conclusion The high proportion of NTDs with monogenic background underlines the importance of a syndrome oriented fetal pathology. At the very least it requires a thourough photographic and radiographic documentation of the fetal phenotype to enable the genetic counsellor to identify a syndromic disorder. This is necessary to determine the risk of recurrence, arrange confirming mutation analyses and offer targeted prenatal diagnosis in subsequent pregnancies.

The increased use of array-CGH and SNP-arrays for genetic diagnosis has led to the identification of new microdeletion/microduplication syndromes and enabled genotype-phenotype correlations to be made. In this study, nine patients with 9q21 deletions were investigated and compared with four previously Decipher reported patients. Genotype-phenotype comparisons of 13 patients revealed several common major characteristics including significant developmental delay, epilepsy, neuro-behavioural disorders and recognizable facial features including hypertelorism, feature-less philtrum, and a thin upper lip. The molecular investigation identified deletions with different breakpoints and of variable lengths, but the 750 kb smallest overlapping deleted region includes four genes. Among these genes, RORB is a strong candidate for a neurological phenotype. To our knowledge, this is the first published report of 9q21 microdeletions and our observations strongly suggest that these deletions are responsible for a new genetic syndrome characterised by mental retardation with speech delay, epilepsy, autistic behaviour and moderate facial dysmorphy.

X-linked intellectual disability (XLID) is a genetically heterogeneous disorder with more than 100 genes known to date. Most genes are responsible for a small proportion of patients only, which has hitherto hampered the systematic screening of large patient cohorts. We performed targeted enrichment and next-generation sequencing of 107 XLID genes in a cohort of 150 male patients. Hundred patients had sporadic intellectual disability, and 50 patients had a family history suggestive of XLID. We also analysed a sporadic female patient with severe ID and epilepsy because she had strongly skewed X-inactivation. Target enrichment and high parallel sequencing allowed a diagnostic coverage of >10 reads for ~96% of all coding bases of the XLID genes at a mean coverage of 124 reads. We found 18 pathogenic variants in 13 XLID genes (AP1S2, ATRX, CUL4B, DLG3, IQSEC2, KDM5C, MED12, OPHN1, SLC9A6, SMC1A, UBE2A, UPF3B and ZDHHC9) among the 150 male patients. Thirteen pathogenic variants were present in the group of 50 familial patients (26%), and 5 pathogenic variants among the 100 sporadic patients (5%). Systematic gene dosage analysis for low coverage exons detected one pathogenic hemizygous deletion. An IQSEC2 nonsense variant was detected in the female ID patient, providing further evidence for a role of this gene in encephalopathy in females. Skewed X-inactivation was more frequently observed in mothers with pathogenic variants compared with those without known X-linked defects. The mutation rate in the cohort of sporadic patients corroborates previous estimates of 5–10% for X-chromosomal defects in male ID patients.

Heterozygous loss of function mutations in CHD7 (chromodomain helicase DNA-binding protein 7) lead to CHARGE syndrome, a complex developmental disorder affecting craniofacial structures, cranial nerves and several organ systems. Recently, it was demonstrated that CHD7 is essential for the formation of multipotent migratory neural crest cells, which migrate from the neural tube to many regions of the embryo, where they differentiate into various tissues including craniofacial and heart structures. So far, only few CHD7 target genes involved in neural crest cell development have been identified and the role of CHD7 in neural crest cell guidance and the regulation of mesenchymal-epithelial transition are unknown. Therefore, we undertook a genome-wide microarray expression analysis on wild-type and CHD7 deficient (Chd7 (Whi/+) and Chd7 (Whi/Whi) ) mouse embryos at day 9.5, a time point of neural crest cell migration. We identified 98 differentially expressed genes between wild-type and Chd7 (Whi/Whi) embryos. Interestingly, many misregulated genes are involved in neural crest cell and axon guidance such as semaphorins and ephrin receptors. By performing knockdown experiments for Chd7 in Xenopus laevis embryos, we found abnormalities in the expression pattern of Sema3a, a protein involved in the pathogenesis of Kallmann syndrome, in vivo. In addition, we detected non-synonymous SEMA3A variations in 3 out of 45 CHD7-negative CHARGE patients. In summary, we discovered for the first time that Chd7 regulates genes involved in neural crest cell guidance, demonstrating a new aspect in the pathogenesis of CHARGE syndrome. Furthermore, we showed for Sema3a a conserved regulatory mechanism across different species, highlighting its significance during development. Although we postulated that the non-synonymous SEMA3A variants which we found in CHD7-negative CHARGE patients alone are not sufficient to produce the phenotype, we suggest an important modifier role for SEMA3A in the pathogenesis of this multiple malformation syndrome.

Biallelic mutations in the gene encoding DHOdehase [dihydroorotate dehydrogenase (DHODH)], an enzyme required for de novo pyrimidine biosynthesis, have been identified as the cause of Miller (Genee-Weidemann or postaxial acrofacial dysostosis) syndrome (MIM 263750). We report compound heterozygous DHODH mutations in four additional families with typical Miller syndrome. Complementation in auxotrophic yeast demonstrated reduced pyrimidine synthesis and in vitro enzymatic analysis confirmed reduced DHOdehase activity in 11 disease-associated missense mutations, with 7 alleles showing discrepant activity between the assays. These discrepancies are partly explained by the domain structure of DHODH and suggest both assays are useful for interpretation of individual alleles. However, in all affected individuals, the genotype predicts that there should be significant residual DHOdehase activity. Urine samples obtained from two mutation-positive cases showed elevated levels of orotic acid (OA) but not dihydroorotate (DHO), an unexpected finding since these represent the product and the substrate of DHODH enzymatic activity, respectively. Screening of four unrelated cases with overlapping but atypical clinical features showed no mutations in either DHODH or the other de novo pyrimidine biosynthesis genes (CAD, UMPS), with these cases also showing normal levels of urinary OA and DHO. In situ analysis of mouse embryos showed Dhodh, Cad and Umps to be strongly expressed in the pharyngeal arch and limb bud, supporting a site- and stage-specific requirement for de novo pyrimidine synthesis. The developmental sensitivity to reduced pyrimidine synthesis capacity may reflect the requirement for an exceptional mitogenic response to growth factor signalling in the affected tissues.

Contains fulltext : 88233.pdf (Publisher’s version ) (Closed access) Cleidocranial Dysplasia (CCD) is an autosomal dominant skeletal disorder characterized by hypoplastic or absent clavicles, increased head circumference, large fontanels, dental anomalies, and short stature. Hand malformations are also common. Mutations in RUNX2 cause CCD, but are not identified in all CCD patients. In this study we screened 135 unrelated patients with the clinical diagnosis of CCD for RUNX2 mutations by sequencing analysis and demonstrated 82 mutations 48 of which were novel. By quantitative PCR we screened the remaining 53 unrelated patients for copy number variations in the RUNX2 gene. Heterozygous deletions of different size were identified in 13 patients, and a duplication of the exons 1 to 4 of the RUNX2 gene in one patient. Thus, heterozygous deletions or duplications affecting the RUNX2 gene may be present in about 10% of all patients with a clinical diagnosis of CCD which corresponds to 26% of individuals with normal results on sequencing analysis. We therefore suggest that screening for intragenic deletions and duplications by qPCR or MLPA should be considered for patients with CCD phenotype in whom DNA sequencing does not reveal a causative RUNX2 mutation. 01 augustus 2010