The authors report the frequency and the clinical signs of uniparental disomy of chromosome 7 in Silver-Russell syndrome patients. A cohort of 73 families were typed with Short Tandem Repeat markers from chromosomes 7. In 6 patients maternal uniparental disomy 7 (UPD7) was detected. Summarising their data and those from the literature, an overall frequency of maternal uniparental disomy 7 of approximately 10% can be estimated. Allelic distribution in two of their maternal uniparental disomy 7 families indicates complete isodisomy whereas allelic patterns in the other four families are consistent with partial and complete heterodisomy, respectively. The clinical features of maternal uniparental disomy 7 patients do not show any deviation from the non-uniparental disomy 7 patients. Additionally, there was not hint for possible influences of iso- or heterodisomy, possibly associated with different stages of mosaicism. Their results demonstrate the necessity to screen SRS patients for UPD7 although the effect of UPD7 cannot be correlated to the SRS phenotype yet. Furthermore, an association between UPD for chromosomes other than 7 and SRS seems to be negligible. Vice versa, maternal UPD7 is not detectable in non-SRS patients. Therefore, testing for maternal UPD7 can be restricted to SRS families, searching for other UPDs in this population does not seem to be reasonable. Additionally, cytogenetic analysis should also be performed in SRS patients: identification of commonly involved chromosomal regions should allow narrowing down a SRS-relevant region.
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J Assist Reprod Genet
January 2025
Department of Human Genetic, Altamedica, Rome, Italy.
Genes (Basel)
December 2024
Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland.
: Neural retina leucine zipper (NRL) is a transcription factor involved in the differentiation of rod photoreceptors. Pathogenic variants in the gene encoding NRL have been associated with autosomal dominant retinitis pigmentosa and autosomal recessive clumped pigmentary retinal degeneration. Only a dozen unrelated families affected by recessive -related retinal dystrophy have been described.
View Article and Find Full Text PDFPrenat Diagn
December 2024
Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Francisco, San Francisco, California, USA.
Front Endocrinol (Lausanne)
December 2024
Rare Disease Research Group, Molecular (Epi) Genetics Laboratory, Bioaraba Health Research Institute, Araba University Hospital, Vitoria-Gasteiz, Spain.
Objective: To identify the genetic cause underlying the methylation defect in a patient with clinical suspicion of PHP1B/iPPSD3.
Design: Imprinting is an epigenetic mechanism that allows the regulation of gene expression. The locus is one of the loci within the genome that is imprinted.
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