Myelinated retinal fibers in autosomal recessive spastic ataxia of Charlevoix-Saguenay.

  Myelinated retinal nerve fibers are considered a hallmark of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) in French Canadian patients. The demonstration of a worldwide distribution of this disease, as well as the almost invariable presence of a normal retina on fundoscopy in cases outside Canada, suggests that more quantitative methodologies are needed to assess the retina in ARSACS.  To characterize better the retinal features of ARSACS, we studied five Italian patients by means of optical coherence tomography (OCT), a processing method that allows the creation of three-dimensional images with micrometer resolution. We compared OCT characteristics in ARSACS with those obtained from five subjects with persistent myelination of the retina, a rare congenital non-progressive anomaly.  Four patients with ARSACS showed myelinated retinal nerve fibers on ophthalmoscopy, corresponding to an increased thickness of the retina on OCT, a characteristic not present in the subjects with persistent myelination of the retina.  Myelinated retinal fibers are not rare in Italian patients with ARSACS. This finding may be the consequence of the thickening of the retina, as detected by OCT

Exon deletions of the phenylalanine hydroxylase gene in Italian hyperphenylalaninemics

A consistent finding of many studies describing the spectrum of mutant phenylalanine hydroxylase (PAH) alleles underlying hyperphenylalaninemia is the impossibility of achieving a 100% mutation ascertainment rate using conventional gene-scanning methods. These methods include denaturing gradient gel electrophoresis (DGGE), denaturing high performance liquid chromatography (DHPLC), and direct sequencing. In recent years, it has been shown that a significant proportion of undetermined alleles consist of large deletions overlapping one or more exons. These deletions have been difficult to detect in compound heterozygotes using gene-scanning methods due to a masking effect of the non-deleted allele. To date, no systematic search has been carried out for such exon deletions in Italian patients with phenylketonuria or mild hyperphenylalaninemia. We used multiplex ligation- dependent probe amplification (MLPA), comparative multiplex dosage analysis (CMDA), and real-time PCR to search for both large deletions and duplications of the phenylalanine hydroxylase gene in Italian hyperphenylalaninemia patients. Four deletions removing different phenylalanine hydroxylase (PAH) gene exons were identified in 12 patients. Two of these deletions involving exons 4-5-6-7-8 (systematic name c.353-?_912 + ?del) and exon 6 (systematic name c.510-?_706 + ?del) have not been reported previously. In this study, we show that exon deletion of the PAH gene accounts for 1.7% of all mutant PAH alleles in Italian hyperphenylalaninemics

A 43-year-old man with persistent fever and sudden shortness of breath.

A 43-year-old white man with a 3-week history of nonproductive cough, wheezing, and chest pain was treated with a standard regimen of oral antibiotics in the primary care setting with little clinical improvement of symptoms and then was admitted to the ED of our hospital for acute onset of shortness of breath. He had an otherwise unremarkable medical history, with the exception of chest trauma 3 years prior to admission. He had a smoking history of 18 pack-years and had quit smoking 26 years prior to presentation. Working in a slaughterhouse for 15 years had given him a long occupational exposure to cattl

NGS in Hereditary Ataxia: When Rare Becomes Frequent

The term hereditary ataxia (HA) refers to a heterogeneous group of neurological disorders with multiple genetic etiologies and a wide spectrum of ataxia-dominated phenotypes. Massive gene analysis in next-generation sequencing has entered the HA scenario, broadening our genetic and clinical knowledge of these conditions. In this study, we employed a targeted resequencing panel (TRP) in a large and highly heterogeneous cohort of 377 patients with a clinical diagnosis of HA, but no molecular diagnosis on routine genetic tests. We obtained a positive result (genetic diagnosis) in 33.2% of the patients, a rate significantly higher than those reported in similar studies employing TRP (average 19.4%), and in line with those performed using exome sequencing (ES, average 34.6%). Moreover, 15.6% of the patients had an uncertain molecular diagnosis. STUB1, PRKCG, and SPG7 were the most common causative genes. A comparison with published literature data showed that our panel would have identified 97% of the positive cases reported in previous TRP-based studies and 92% of those diagnosed by ES. Proper use of multigene panels, when combined with detailed phenotypic data, seems to be even more efficient than ES in clinical practice

Diagnostic Targeted Resequencing in 349 Patients with Drug-Resistant Pediatric Epilepsies Identifies Causative Mutations in 30 Different Genes

Targeted resequencing gene panels are used in the diagnostic setting to identify gene defects in epilepsy. We performed targeted resequencing using a 30-genes panel and a 95-genes panel in 349 patients with drug-resistant epilepsies beginning in the first years of life. We identified 71 pathogenic variants, 42 of which novel, in 30 genes, corresponding to 20.3% of the probands. In 66% of mutation positive patients, epilepsy onset occurred before the age of 6 months. The 95-genes panel allowed a genetic diagnosis in 22 (6.3%) patients that would have otherwise been missed using the 30-gene panel. About 50% of mutations were identified in genes coding for sodium and potassium channel components. SCN2A was the most frequently mutated gene followed by SCN1A, KCNQ2, STXBP1, SCN8A, CDKL5, and MECP2. Twenty-nine mutations were identified in 23 additional genes, most of them recently associated with epilepsy. Our data show that panels targeting about 100 genes represent the best cost-effective diagnostic option in pediatric drug-resistant epilepsies. They enable molecular diagnosis of atypical phenotypes, allowing to broaden phenotype\u2013genotype correlations. Molecular diagnosis might influence patients' management and translate into better and specific treatment recommendations in some conditions