163 research outputs found
Prenatal diagnosis and follow-up of a case of branchio-oto-renal syndrome displays renal growth impairment after the second trimester
Branchio-oto-renal syndrome combines branchial arch defects, hearing impairment and renal malformations or hypoplasia. Due to the high phenotypic variability, prenatal diagnosis has a limited prognostic value in mutation-positive cases. We report the first branchio-oto-renal syndrome molecular prenatal diagnosis and ultrasonographic follow-up, showing a normal renal growth until the 24th week of pregnancy, a growth deceleration during the third trimester and a renal volume recovery during the first months of life
Second Trimester Amniocentesis Is Not a Risk Factor for Very Low Birth Weight and Extremely Low Birth Weight
Objectives. To assess the risk of very low birth weight (VLBW) and extremely low birth weight (ELBW) attributable to second trimester amniocentesis. Methods. Records of 4,877 consecutive amniocentesis, performed between 1997 and 2003, were analyzed. Only VLBW and ELBW in the study population (exposed) and in the control group (unexposed) were evaluated. Comparisons were made between the amniocentesis group versus nonexposed. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated for VLBW and ELBW classes. Results. In the study population, the VLBW were 35 (0.71%) and the ELBW were 20 (0.41%). In the control group, the VLBW were 220 (0.67%) and the ELBW were 112 (0.34%). The Odds ratios of the VLBW between the study and the control group did not show any statistical significant risk (OR = 1.07, 95% CI = 0.72–1.54). Also in ELBW odds ratios between study and control group were not statistically significant (OR = 1.20, 95% CI = 0.7–1.95). Conclusions. No effect of the second trimester amniocentesis was noted on VLBW and ELBW
A new MEFV gene mutation in an Iranian patient with familial Mediterranean fever.
Familial mediterranean fever (FMF) is an inherited autoinflammatory disorder characterized by recurrent episodes of fever and painful inflammation involving the intra-abdominal organs, the lungs and the joints, which is highly prevalent in specific ethnic groups including the Iranians. We report a 12-year-old boy from Iran, with a clinical history of recurrent fever. Based on the suggestive clinical data, mutational analysis revealed the presence of the novel c.1945C>T heterozygous variant in exon 10, which leads to a leucine to phenylalanine change at position 649 of the protein. The mutation was inherited from the mother. This novel mutation lies in exon 10 of the MEFV gene, which encodes for a domain called B30.2-SPRY, located in the C-terminal region of the pyrin protein and contains the most frequent mutations associated with FMF. The present report expands the spectrum of MEFV gene mutations associated with FMF. The uniqueness of this study, compared with other published case reports, consists in the new mutation found in the MEFV gene. In fact, new mutations in this gene are of high interest, in order to better understand the role of this gene in autoinflammation
Melorheostosis and Osteopoikilosis Clinical and Molecular Description of an Italian Case Series
Melorheostosis (MEL) is an uncommon, sclerosing disease, characterised by hyperostosis of long bones, resembling the flowing of candle wax. The disease is sporadic and the pathogenesis is still poorly understood. Occasionally, the same family can include individuals with MEL and Osteopoikilosis (OPK), a disease characterised by multiple round foci of increased bone density. LEMD3 gene mutations are related to OPK and Buschke–Ollendorff Syndrome, a genetic condition in which an association between MEL, OPK and skin lesions is observed. In rare cases, LEMD3 mutations and recently mosaic MAP2K1 gene mutations have been correlated to MEL suggesting that somatic mosaicism could be causative of the disease. In this study, we described the clinical, radiological and molecular findings of 19 individuals with MEL and 8 with OPK and compared the results to the medical literature. The molecular analyses of this case series corroborate the available data in the medical literature, indicating that LEMD3 germline mutations are not a major cause of isolated MEL and reporting five further cases of OPK caused by LEMD3 germline mutations
Molecular Genetic Analysis of the PLP1 Gene in 38 Families with PLP1-related disorders: Identification and Functional Characterization of 11 Novel PLP1 Mutations
<p>Abstract</p> <p>Background</p> <p>The breadth of the clinical spectrum underlying Pelizaeus-Merzbacher disease and spastic paraplegia type 2 is due to the extensive allelic heterogeneity in the X-linked <it>PLP1 </it>gene encoding myelin proteolipid protein (PLP). <it>PLP1 </it>mutations range from gene duplications of variable size found in 60-70% of patients to intragenic lesions present in 15-20% of patients.</p> <p>Methods</p> <p>Forty-eight male patients from 38 unrelated families with a PLP1-related disorder were studied. All DNA samples were screened for <it>PLP1 </it>gene duplications using real-time PCR. <it>PLP1 </it>gene sequencing analysis was performed on patients negative for the duplication. The mutational status of all 14 potential carrier mothers of the familial <it>PLP1 </it>gene mutation was determined as well as 15/24 potential carrier mothers of the <it>PLP1 </it>duplication.</p> <p>Results and Conclusions</p> <p><it>PLP1 </it>gene duplications were identified in 24 of the unrelated patients whereas a variety of intragenic <it>PLP1 </it>mutations were found in the remaining 14 patients. Of the 14 different intragenic lesions, 11 were novel; these included one nonsense and 7 missense mutations, a 657-bp deletion, a microdeletion and a microduplication. The functional significance of the novel <it>PLP1 </it>missense mutations, all occurring at evolutionarily conserved residues, was analysed by the <it>MutPred </it>tool whereas their potential effect on splicing was ascertained using the <it>Skippy </it>algorithm and a neural network. Although <it>MutPred </it>predicted that all 7 novel missense mutations would be likely to be deleterious, <it>in silico </it>analysis indicated that four of them (p.Leu146Val, p.Leu159Pro, p.Thr230Ile, p.Ala247Asp) might cause exon skipping by altering exonic splicing elements. These predictions were then investigated <it>in vitro </it>for both p.Leu146Val and p.Thr230Ile by means of RNA or minigene studies and were subsequently confirmed in the case of p.Leu146Val. Peripheral neuropathy was noted in four patients harbouring intragenic mutations that altered RNA processing, but was absent from all <it>PLP1</it>-duplication patients. Unprecedentedly, family studies revealed the <it>de novo </it>occurrence of the <it>PLP1 </it>duplication at a frequency of 20%.</p
Unmasking selective path integration deficits inAlzheimer’s disease risk carriers
Alzheimer’s disease (AD) manifests with progressive memory loss and spatial disorientation. Neuropathological studies suggest early AD pathology in the entorhinal cortex (EC) of young adults at genetic risk for AD (APOE4-carriers). Because the EC harbors grid cells, a likely neural substrate of path integration (PI), we examined PI performance in APOE4-carriers during a virtual navigation task. We report a selective impairment in APOE4-carriers specifically when recruitment of compensatory navigational strategies via supportive spatial cues was disabled. A separate fMRI study revealed that PI performance was associated with the strength of entorhinal grid-like representations when no compensatory strategies were available, suggesting grid cell dysfunction as a mechanistic explanation for PI deficits in APOE4-carriers. Furthermore, posterior cingulate/retrosplenial cortex was involved in the recruitment of compensatory navigational strategies via supportive spatial cues. Our results provide evidence for selective PI deficits in AD risk carriers, decades before potential disease onset
Hypomelanosis of Ito with a trisomy 2 mosaicism: a case report
Introduction: Hypomelanosis of Ito is a rare neurocutaneous disorder, characterized by streaks and swirls of hypopigmentation following the lines of Blaschko that may be associated to systemic abnormalities involving the central nervous system and musculoskeletal system. Despite the preponderance of reported sporadic hypomelanosis of Ito, few reports of familial hypomelanosis of Ito have been described. Case presentation: A 6-month-old Caucasian girl presented with unilateral areas of hypomelanosis distributed on the left half of her body and her father presented with similar mosaic hypopigmented lesions on his upper chest. Whereas both blood karyotypes obtained from peripheral lymphocyte cultures were normal, a 16% trisomy 2 mosaicism was found in cultured skinfibroblasts derived from a hypopigmented skin area of her father. Conclusions: Familial cases of hypomelanosis of Ito are very rare and can occur in patients without systemic involvement. Hypomelanosis of Ito constitutes a non-specific diagnostic definition including different clinical entities with a wide phenotypic variability, either sporadic or familial. Unfortunately, a large number of cases remain misdiagnosed due to both diagnostic challenges and controversial issues on cutaneous biopsies in the pediatric population
Involvement of MBD4 inactivation in mismatch repair-deficient tumorigenesis
The DNA glycosylase gene MBD4 safeguards genomic stability at CpG sites and is frequently mutated at coding poly-A tracks in mismatch repair (MMR)-defective colorectal tumors (CRC). Mbd4 biallelic inactivation in mice provided conflicting results as to its role in tumorigenesis. Thus, it is unclear whether MBD4 alterations are only secondary to MMR defects without functional consequences or can contribute to the mutator phenotype. We investigated MBD4 variants in a large series of hereditary/familial and sporadic CRC cases. Whereas MBD4 frameshifts were only detected in tumors, missense variants were found in both normal and tumor DNA. In CRC with double-MBD4/MMR and single-MBD4 variants, transition mutation frequency was increased, indicating that MBD4 defects may affect the mutational landscape independently of MMR defect. Mbd4-deficient mice showed reduced survival when combined with Mlh1−/− genotype. Taken together, these data suggest that MBD4 inactivation may contribute to tumorigenesis, acting as a modifier of MMR-deficient cancer phenotype
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