BackgroundHepcidin plays a key role in body iron metabolism by preventing the release of iron from macrophages and intestinal cells. Defective hepcidin synthesis causes iron loading, while overproduction results in defective reticuloendothelial iron release and iron absorption.
in 57%, duplications in 11% and small mutations in 32%. In BMD, we found deletions in 78%, duplications in 9% and small mutations in 13%. In BMD, there are a higher number of deletions, and small mutations are more frequent than duplications. Among small mutations that are generally frequent in both phenotypes, 44% of DMD and 36% of BMD are nonsense, thus, eligible for stop codon read-through therapy; 63% of all out-of-frame deletions are eligible for single exon skipping. Patients were also assigned to Italian regions and showed interesting regional differences in mutation distribution. The full genetic characterization in this large, nationwide cohort has allowed us to draw several correlations between DMD/BMD genotype landscapes and mutation frequency, mutation types, mutation locations along the gene, exon/intron architecture, and relevant protein d o m a i n , w i t h e ff e c t s on p o p u l a t i o n ge n e t i c c h a r a c t e r i s t i c s a n d ne w personalized therapies.
Two new cases of dilated cardiomyopathy (DC) caused by dystrophinopathy are reported. One patient, a 24 year old man, had a family history of X linked DC, while the other, a 52 year old man, had sporadic disease. Each had abnormal dystrophin immunostaining in muscle or cardiac biopsy specimens, but neither had muscle weakness. Serum creatine kinase activity was raised only in the patient with familial disease. Analysis of dystrophin gene mutations showed a deletion of exons 48-49 in the patient with familial DC and of exons 49-51 in the other. Dystrophin transcription in cardiac tissue from the patient with sporadic disease showed abundant expression, predominantly of the muscle isoform. This study, together with previous reports, suggests that some patients with DC have a dystrophinopathy that can be diagnosed using a combination of biochemical and genetic analyses.
In mammals, X-linked gene products can be dosage compensated between males and females by inactivation of one of the two X chromosomes in the developing female embryos. X inactivation choice is usually random in embryo mammals, but several mechanisms can influence the choice determining skewed X inactivation. As a consequence, females heterozygous for X-linked recessive disease can manifest the full phenotype. Herein, we report a family with extremely skewed X inactivation that produced the full phenotype of Lowe syndrome, a recessive X-linked disease, in a female. The X chromosome inactivation studies detected an extremely skewed inactivation pattern with a ratio of 100:0 in the propositus as well as in five out of seven unaffected female relatives in four generations. The OCRL1 ''de novo'' mutation resides in the active paternally inherited X chromosome. X chromosome haplotype analysis suggests the presence of a locus for the familial skewed X inactivation in chromosome Xq25 most likely controlling X chromosome choice in X inactivation or cell proliferation. The description of this case adds Lowe syndrome to the list of X-linked disorders which may manifest the full phenotype in females because of the skewed X inactivation.
The oculocerebrorenal syndrome of Lowe (OCRL, also called OCRL1) is a rare X-linked disorder characterized by major abnormalities of eyes, nervous system, and kidneys. The gene responsible for OCRL was identified by positional cloning and encodes an inositol polyphosphate-5-phosphatase. We performed the molecular analysis in 9 Italian patients and 26 relatives and we detected the mutations in all the examined patients. Eight mutations out of nine had never been described and consisted of truncating mutations (frameshift, nonsense, splice site and genomic deletion), and missense mutations. The mutations were distributed in the second half of the gene as previously described in other populations. In three cases the mutations were absent in the mothers confirming the occurrence of novel mutations in this disorder. Our results on the Italian population are similar to the data previously obtained in other populations.
Genetic testing of myotonic dystrophy type 1 (DM1) is very important because it enables the diagnosis and indicates the severity of the disease. Mutation analysis is based on the detection of the number of CTG triplets in the 3' untranslated region of the myotonic dystrophy protein kinase (DMPK) gene. Sometimes it could be complicated by the presence of different patterns of repeat interruptions in the 5' and 3' ends of the expanded alleles recently described in about 3% to 5% of patients. To make molecular diagnosis easier and faster, the use of triplet-primed PCR (TP-PCR) for the detection of expansions in DM1 and other dynamic mutation diseases was proposed. Here we present the results of a retrospective study performed by TP-PCR on 100 subjects previously analyzed by Southern blotting-long PCR.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.