RESUMO
BACKGROUND: Ciliopathies are an extensive group of autosomal recessive or X-linked disorders with considerable genetic and clinical overlap, which collectively share multiple organ involvement and may result in lethal or viable phenotypes. In large numbers of cases the genetic defect remains yet to be determined. The aim of this study is to describe the mutational frequency and phenotypic spectrum of the CEP120 gene. METHODS: Exome sequencing was performed in 145 patients with Joubert syndrome (JS), including 15 children with oral-facial-digital syndrome type VI (OFDVI) and 21 Meckel syndrome (MKS) fetuses. Moreover, exome sequencing was performed in one fetus with tectocerebellar dysraphia with occipital encephalocele (TCDOE), molar tooth sign and additional skeletal abnormalities. As a parallel study, 346 probands with a phenotype consistent with JS or related ciliopathies underwent next-generation sequencing-based targeted sequencing of 120 previously described and candidate ciliopathy genes. RESULTS: We present six probands carrying nine distinct mutations (of which eight are novel) in the CEP120 gene, previously found mutated only in Jeune asphyxiating thoracic dystrophy (JATD). The CEP120-associated phenotype ranges from mild classical JS in four patients to more severe conditions in two fetuses, with overlapping features of distinct ciliopathies that include TCDOE, MKS, JATD and OFD syndromes. No obvious correlation is evident between the type or location of identified mutations and the ciliopathy phenotype. CONCLUSION: Our findings broaden the spectrum of phenotypes caused by CEP120 mutations that account for nearly 1% of patients with JS as well as for more complex ciliopathy phenotypes. The lack of clear genotype-phenotype correlation highlights the relevance of comprehensive genetic analyses in the diagnostics of ciliopathies.
Assuntos
Anormalidades Múltiplas/genética , Proteínas de Ciclo Celular/genética , Cerebelo/anormalidades , Anormalidades do Olho/genética , Doenças Renais Císticas/genética , Mutação/genética , Retina/anormalidades , Sequência de Aminoácidos , Doenças Cerebelares/genética , Criança , Ciliopatias/genética , Encefalocele/genética , Feminino , Estudos de Associação Genética/métodos , Predisposição Genética para Doença/genética , Testes Genéticos/métodos , Humanos , Masculino , Taxa de Mutação , Síndromes Orofaciodigitais/genética , Linhagem , Fenótipo , Alinhamento de SequênciaRESUMO
OBJECTIVE: Antiepileptic drugs (AED) have chronic teratogenic effects, the most common of which are congenital heart disease, cleft lip/palate, urogenital and neural tube defects. The aim of our study is to examine teratogenic effects of AED and the correlation between these malformations and AED in single or multiple pregnancies. METHODS: This is a retrospective study of malformations in children born to mothers currently followed up by our outpatient clinics who used or discontinued AED during their pregnancy. Their children were then investigated using echocardiography, urinary ultrasound, cranial magnetic resonance image, and examined by geneticists and pediatric dentists. RESULTS: One hundred and seventeen children were included in the study. Ninety one of these children were exposed to AED during pregnancy. The most commonly used AED were valproic acid and carbamazepine in monotherapy. The percentage of major anomaly was 6.8% in all children. Dysmorphic features and dental anomalies were observed more in children exposed especially to valproic acid. There were 26 mothers with two and four mothers with three pregnancies from the same fathers. No correlation was found between the distribution of malformations in recurring pregnancies and AED usage. CONCLUSION: Our study has the highest number of dysmorphism examined in literature, found in all the children exposed to valproic acid, which may account for the higher rate of facial dysmorphism and dental anomalies. On lower doses of valproic acid, major malformations are not seen, although the risk increases with polytherapy. Our data also indicate possible effects of genetic and environmental factors on malformations.
RESUMO
Phosphotidylinositol (PtdIns) signaling is tightly regulated both spatially and temporally by subcellularly localized PtdIns kinases and phosphatases that dynamically alter downstream signaling events. Joubert syndrome is characterized by a specific midbrain-hindbrain malformation ('molar tooth sign'), variably associated retinal dystrophy, nephronophthisis, liver fibrosis and polydactyly and is included in the newly emerging group of 'ciliopathies'. In individuals with Joubert disease genetically linked to JBTS1, we identified mutations in the INPP5E gene, encoding inositol polyphosphate-5-phosphatase E, which hydrolyzes the 5-phosphate of PtdIns(3,4,5)P3 and PtdIns(4,5)P2. Mutations clustered in the phosphatase domain and impaired 5-phosphatase activity, resulting in altered cellular PtdIns ratios. INPP5E localized to cilia in major organs affected by Joubert syndrome, and mutations promoted premature destabilization of cilia in response to stimulation. These data link PtdIns signaling to the primary cilium, a cellular structure that is becoming increasingly recognized for its role in mediating cell signals and neuronal function.