LAMA2 loss-of-function mutation in a girl with a mild congenital muscular dystrophy.

The authors report a girl with autosomal recessive congenital muscular dystrophy linked to chromosome 6 (MDC1A) who carries a homozygous out-of-frame deletion in exon 56 of the LAMA2 gene but has a mild phenotype. She is still ambulant at age 13 years, shows white matter abnormalities on MRI, and traces of laminin alpha2 in her muscle biopsy with one of three antibodies used. This patient suggests that modulating factors can be associated with a less severe clinical phenotype in MDC1A.

Mutations in the fukutin-related protein gene (FKRP) identify limb girdle muscular dystrophy 2I as a milder allelic variant of congenital muscular dystrophy MDC1C.

The limb girdle and congenital muscular dystrophies (LGMD and CMD) are characterized by skeletal muscle weakness and dystrophic muscle changes. The onset of symptoms in CMD is within the first few months of life, whereas in LGMD they can occur in late childhood, adolescence or adult life. We have recently demonstrated that the fukutin-related protein gene (FKRP) is mutated in a severe form of CMD (MDC1C), characterized by the inability to walk, leg muscle hypertrophy and a secondary deficiency of laminin alpha2 and alpha-dystroglycan. Both MDC1C and LGMD2I map to an identical region on chromosome 19q13.3. To investigate whether these are allelic disorders, we undertook mutation analysis of FKRP in 25 potential LGMD2I families, including some with a severe and early onset phenotype. Mutations were identified in individuals from 17 families. A variable reduction of alpha-dystroglycan expression was observed in the skeletal muscle biopsy of all individuals studied. In addition, several cases showed a deficiency of laminin alpha2 either by immunocytochemistry or western blotting. Unexpectedly, affected individuals from 15 families had an identical C826A (Leu276Ileu) mutation, including five that were homozygous for this change. Linkage analysis identified at least two possible haplotypes in linkage disequilibrium with this mutation. Patients with the C826A change had the clinically less severe LGMD2I phenotype, suggesting that this is a less disruptive FKRP mutation than those found in MDC1C. The spectrum of LGMD2I phenotypes ranged from infants with an early presentation and a Duchenne-like disease course including cardiomyopathy, to milder phenotypes compatible with a favourable long-term outcome.

Mutations in the fukutin-related protein gene (FKRP) cause a form of congenital muscular dystrophy with secondary laminin alpha2 deficiency and abnormal glycosylation of alpha-dystroglycan.

The congenital muscular dystrophies (CMD) are a heterogeneous group of autosomal recessive disorders presenting in infancy with muscle weakness, contractures, and dystrophic changes on skeletal-muscle biopsy. Structural brain defects, with or without mental retardation, are additional features of several CMD syndromes. Approximately 40% of patients with CMD have a primary deficiency (MDC1A) of the laminin alpha2 chain of merosin (laminin-2) due to mutations in the LAMA2 gene. In addition, a secondary deficiency of laminin alpha2 is apparent in some CMD syndromes, including MDC1B, which is mapped to chromosome 1q42, and both muscle-eye-brain disease (MEB) and Fukuyama CMD (FCMD), two forms with severe brain involvement. The FCMD gene encodes a protein of unknown function, fukutin, though sequence analysis predicts it to be a phosphoryl-ligand transferase. Here we identify the gene for a new member of the fukutin protein family (fukutin related protein [FKRP]), mapping to human chromosome 19q13.3. We report the genomic organization of the FKRP gene and its pattern of tissue expression. Mutations in the FKRP gene have been identified in seven families with CMD characterized by disease onset in the first weeks of life and a severe phenotype with inability to walk, muscle hypertrophy, marked elevation of serum creatine kinase, and normal brain structure and function. Affected individuals had a secondary deficiency of laminin alpha2 expression. In addition, they had both a marked decrease in immunostaining of muscle alpha-dystroglycan and a reduction in its molecular weight on western blot analysis. We suggest these abnormalities of alpha-dystroglycan are caused by its defective glycosylation and are integral to the pathology seen in MDC1C.

[IgE-mediated allergy to ethylene oxide in hemodialyzed patients]. / Allergia IgE-mediata verso l'ossido di etilene nei pazienti emodializzati.

Ethylene oxide (ETO) is widely employed in sterilization of hemodialysis materials. Many studies have shown that ETO may act as an antigenic compound when bound to human albumin, therefore eliciting allergic reactions during hemodialysis. In the present study, we investigated in 93 patients undergoing long-term hemodialysis the prevalence of sensitization to ETO. All the patients were investigated for the presence of allergic or pseudo allergic reactions during the treatment. Specific IgE to ETO were found in sera of 3 patients: 1 suffered from urticaria and 1 from glottic edema and hypotension during the dialysis. The third one had non symptoms. The employ of a gamma-rays sterilized filter determined the disappearance of clinical manifestations in the two symptomatic patients, therefore suggesting a pathogenetic role of the specific IgE to ETO in determining the clinical manifestations.

Determination of phenol, m-, o- and p-cresol, p-aminophenol and p-nitrophenol in urine by high-performance liquid chromatography.

A method for the biological monitoring of human exposure to aromatic hydrocarbons, nitrocompounds, amines and phenols has been developed. Phenol, cresols, p-aminophenol, p-nitrophenol and their glucorono- or sulpho-conjugates, were quantified by HPLC; 4-chlorphenol was added as internal standard. After enzymatic hydrolysis, the free compounds were extracted with an organic solvent and analyzed by an isocratic HPLC Perkin Elmer system at ambient temperature and at a flow-rate of 1 ml/min. The column was a reversed-phase Pecosphere 3 x 3 C18 Perkin Elmer; the mobile phase was a 30:70:0.1 (v/v/v) methanol-water-orthophosphoric acid mixture and the chromatogram was monitored at 215 nm. Identification was based on retention time and quantification was performed by automatic peak height determination, corrected for the internal standard. The recovery was ca. 95% for phenol and cresols; 90% for p-nitrophenol; 85% for p-aminophenol; the coefficients of variance were less than 6% within analysis (n = 20) and less than 10% between analysis (n = 20). The detection limits, at a signal/noise ratio of 2, were 0.5 mg/l for phenol and cresols and 1 mg/l for p-aminophenol and p-nitrophenol.

[Sensitization against Parietaria pollen in a group of 1143 patients in the Brescian area]. / Sensibilizzazione verso il polline di Parietaria in una casistica di 1143 pazienti dell'area Bresciana.

1143 patients were selected among atopic outpatients followed up at our Institution (Clinical Immunology-University of Brescia) on the basis of documented sensitization to one or more inhalant allergens. All patients had been investigated by skin prick tests employing a large panel of allergens. Specific sensitization had been confirmed by clinical history and when necessary by RAST. The patients were investigated retrospectively for the prevalence of sensitization to Paretaria. 880 patients were sensitized to one or more pollens and among these 427 (48.5) to Parietaria. Among pollen monosensitized patients (with no concomitant allergy to other inhalants), 222 were sensitized to Graminacee and 125 to Parietaria. In these groups there was no difference in prevalence of asthma. Our study thereby shows that the prevalence of sensitization to Parietaria in Brescia is higher than described in other cities in North Italy. Our findings are supported by pollen concentration in atmosphere as determined by Burkard pollen trap.