Clinical and molecular study in a long-surviving patient with MLASA syndrome due to novel PUS1 mutations.

Myopathy-lactic acidosis-sideroblastic anemia (MLASA) syndrome is a rare autosomal recessive disease. We studied a 43-year-old female presenting since childhood with mild cognitive impairment and sideroblastic anemia. She later developed hepatopathy, cardiomyopathy, and insulin-dependent diabetes. Muscle weakness appeared in adolescence and, at age 43, she was unable to walk. Two novel different mutations in the PUS1 gene were identified: c.487delA (p.I163Lfs*4) and c.884 G>A (p.R295Q). Quantitative analysis of DNA from skeletal muscle biopsies showed a significant increase in mitochondrial DNA (mtDNA) content in the patient compared to controls. Clinical and molecular findings of this patient widen the genotype-phenotype spectrum in MLASA syndrome.

Validation of CFTR intronic variants identified during cystic fibrosis population screening by a minigene splicing assay.

BACKGROUND: Cystic fibrosis, caused by mutations of the CFTR gene, is the most common autosomal recessive condition in the European population and there are specific screening programs aimed at investigating healthy carriers. They are usually articulated in two steps: initially individuals are screened with a panel of the 20-50 most common CFTR mutations; the second step is offered to partners of carriers who were found negative at the first test and consists in the analysis of the entire CFTR gene. This strategy provides high sensitivity, however, it often identifies novel variants (especially in introns) of unknown significance. Establishing the pathogenicity of these variants of the CFTR gene is not a simple task. METHODS: We have examined five CFTR intronic variants of unclear significance (c.274-6T>C, c.744-6T>G, c.1117-64G>A, c.2620-26A>G, and c.3468+51C>A) using a functional splicing assay based on hybrid minigenes. RESULTS: Four out of five variants (including c.2620-26A>G which was previously reported as a possible splice-site mutation) did not alter the correct splicing of the minigene and are likely to be neutral polymorphisms, whereas c.744-6T>G caused complete skipping of CFTR exon 7 and should be therefore regarded as a pathogenic CFTR mutation. CONCLUSIONS: Hybrid minigenes assay are a simple and rapid tool to evaluate the effects of intronic variants without the need of analyzing patient's mRNA, and are particularly suited to analyze variants identified during population screenings.

First-trimester exposure to metformin and risk of birth defects: a systematic review and meta-analysis.

BACKGROUND: Metformin is generally considered a non-teratogenic drug; however, only a few studies specifically designed to assess the rate of congenital anomalies after metformin use have been published in the literature. The objects of the present study were to review all of the prospective and retrospective studies reporting on women treated with metformin at least during the first trimester of their pregnancy and to estimate the overall rate of major birth defects. METHODS: Databases were searched for English language articles until December 2013. Inclusion criteria for the meta-analysis were: a case group of women with PCOS or pre-pregnancy type 2 diabetes and first-trimester exposure to metformin; a disease-matched control group which was not exposed to metformin or other oral anti-diabetic agents; and a list of the major anomalies in both the study and the control groups. A random effects model was used for the meta-analysis of data, using odds ratios. Studies not fulfilling the inclusion criteria for the meta-analysis but reporting relevant data on major malformations in women diagnosed with PCOS were then used to estimate the overall birth defects rate. RESULTS: Meta-analysis of nine controlled studies with women affected by PCOS detected that the rate of major birth defects in the metformin-exposed group was not statistically increased compared with the disease-matched control group and that there was no significant heterogeneity among the studies. The metformin-exposed sample was composed of 351 pregnancies and the OR of major birth defects was 0.86 (95% confidence interval: 0.18-4.08; Pheterogeneity = 0.71). By evaluating all of the non-overlapping PCOS studies reported in the literature, even those without an appropriate control group, the overall rate of major anomalies was 0.6% in the sample of 517 women who discontinued the therapy upon conception or confirmation of pregnancy and 0.5% in the sample of 634 women who were treated with metformin throughout the first trimester of their pregnancy. Regarding type 2 diabetic women, we did not identify a sufficient number of studies with metformin exposure during the first trimester to proceed with the meta-analysis. CONCLUSIONS: There is currently no evidence that metformin is associated with an increased risk of major birth defects in women affected by PCOS and treated during the first trimester. However larger ad hoc studies are warranted in order to definitely confirm the safety and efficacy of this drug in pregnancy.

High-resolution melt as a screening method in autosomal dominant polycystic kidney disease (ADPKD).

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is an inherited condition caused by PKD1 and PKD2 mutations. Complete analysis of both genes is typically required in each patient. In this study, we explored the utility of High-Resolution Melt (HRM) as a tool for mutation analysis of the PKD2 gene in ADPKD families. METHODS: HRM is a mismatch-detection method based on the difference of fluorescence absorbance behavior during the melting of the DNA double strand to denatured single strands in a mutant sample as compared to a reference control. Our families were previously screened by linkage analysis. Subsequently, HRM was used to characterize PKD2-linked families. Amplicons that produced an overlapping profile sample versus wild-type control were not further evaluated, while those amplicons with profile deviated from the control were consequently sequenced. RESULTS: We analyzed 16 PKD2-linked families by HRM analysis. We observed ten different variations: six single-nucleotide polymorphisms and four mutations. The mutations detected by HRM and confirmed by sequencing were as follows: 1158T>A, 2159delA, 2224C>T, and 2533C>T. In particular, the same haplotype block and nonsense mutation 2533C>T was found in 8 of 16 families, so we suggested the presence of a founder effect in our province. CONCLUSIONS: We have developed a strategy for rapid mutation analysis of the PKD2 gene in ADPKD families, which utilizes an HRM-based prescreening followed by direct sequencing of amplicons with abnormal profiles. This is a simple and good technique for PKD2 genotyping and may significantly reduce the time and cost for diagnosis in ADPKD.

14q12 duplication including FOXG1: is there a common age-dependent epileptic phenotype?

INTRODUCTION: Duplications of 14q12 encompassing FOXG1 gene have been recently associated with developmental delay, severe speech impairment, epilepsy, aspecific neuroimaging findings and minor dysmorphisms. AIM AND METHODS: In order to refine the epileptic phenotype associated with 14q12 duplications, we have performed a review of the electroclinical picture of the patients reported to date in the literature, adding a new personal case. A comprehensive set of clinical and instrumental data (with a particular focus on the electroclinical aspects including seizure type, age of onset, EEG at onset and after antiepileptic therapy, drug efficacy) has been taken into account. RESULTS: 9/14 patients carrying 14q12 duplications developed seizures, all in the first months of life. Most of them developed infantile spasms (8/9 epileptic patients) and presented hypsarrhythmia or modified hypsarrhythmia on EEG. After therapy 5/9 patients became seizure free and 3/9 present a good seizure control. At last available follow up, 2/3 of the epileptic patients displayed an almost normal EEG, or a quite organized background activity, with diffuse or focal (mostly temporal) slowing. CONCLUSIONS: The review of the available data allowed to recognize a common epileptic core, characterized by early onset, age dependent epileptic encephalopathy with infantile spasms and typical, atypical or modified hypsarrhythmia. Antiepileptic therapy soon led to a good or complete control of seizures with a nearly normal background activity in most patients.

De novo trisomy 20p characterized by array comparative genomic hybridization: report of a novel case and review of the literature.

We report on a boy with speech delay, mental retardation, motor clumsiness, hyperactivity, dysmorphic facial features, brachytelephalangy and short stature. Electrocardiogram, echocardiography, renal ultrasound, electroencephalogram, fundoscopic exam and auditory brainstem responses were all normal. Brain magnetic resonance imaging showed a left temporal arachnoid cyst and a small pineal gland cyst. High resolution karyotype and FISH analysis detected a de novo duplication of the short arm of chromosome 20. A molecular characterization of the chromosomal anomaly was performed by array-CGH, confirming a 17.98 Mb duplication of the short arm of chromosome 20 associated with a small duplication on chromosome 3p, that was shown to be maternally inherited. This is one of the few cases of de novo trisomy 20p with extensive workup, characterization at molecular level and close follow-up from the neonatal period to age 30 months. We also compared the phenotype of our patient with that previously reported in literature, therefore contributing to better define the trisomy 20p syndrome and helping pediatricians and geneticists to better counsel families about the developmental prognosis of these children.

Pharmacologic treatment of hyperthyroidism during pregnancy.

Clinical hyperthyroidism has been associated with an increased risk of maternal, fetal, and neonatal complications. The available antithyroid drugs are methimazole/carbimazole and propylthiouracil. Several case reports and some epidemiologic studies suggest that methimazole/carbimazole exposure during the first trimester of pregnancy is associated with an increased risk of congenital malformations, including ectodermal anomalies, choanal atresia, esophageal atresia, and omphalocele. However, the absolute risk appears to be very small, and it remains unclear whether the association is driven by the maternal disease, the medication, or the combination of both factors. Propylthiouracil exposure has not been associated with an increased risk of congenital malformations and is the recommended drug during the first trimester of pregnancy. Since propylthiouracil-induced hepatotoxicity has been reported in approximately 0.1% of exposed adults and the number of case-reports of severe liver injury is increasing, treatment with low dose methimazole during the second and third trimesters should be considered. Until now, there has been no evidence that children prenatally exposed to methimazole/carbimazole or propylthiouracil have an increased risk of neurodevelopmental delay.