uniparental disomy

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uniparental disomy



The inheritance of two copies of a chromosome from one parent and none from the other parent. UPD results in a normal number of inherited chromosomes but with inadequate contribution of genetic material from one of the parents. It may result in the expression of recessive genes, as in Prader-Willi syndrome.

uniparental disomy (UPD)

inheritance by offspring of two copies of an homologous chromosome pair from one parent (uniparental) and none from the other parent. Paternal UPD is where both copies are inherited from the father and none from the mother, maternal UPD is where both copies are from the mother and none from the father. There can be two copies of the same chromosome (isodisomy) or one copy of each of the particular parent's chromosomes (heterodisomy). UPD is due to abnormal assortment of chromosomes as a result of NONDISJUNCTION in MEIOSIS and occurs rarely. Health problems associated with UPD include autosomal recessive disorders, such as CYSTIC FIBROSIS, and disorders involving GENOMIC IMPRINTING such as Prader-Willi Syndrome

Uniparental disomy

Chromosome abnormality in which both chromosomes in a pair are inherited from the same parent.
Mentioned in: Prader-Willi Syndrome
References in periodicals archive ?
Diagnostic implications of excessive homozygosity detected by SNP-based microarrays: consanguinity, uniparental disomy, and recessive single-gene mutations.
Mechanisms of mosaicism, chimerism and uniparental disomy identified by single nucleotide polymorphism array analysis.
Research suggests that some people with uniparental disomy do suffer problems related to the genetic duplication within their cells.
Perhaps most intriguing is the possibility that uniparental disomy may cause errors in some prenatal tests for inherited defects.
Agreement 1 C 2 C 3 C 4 P 5 N 6 P 7 C 8 P 9 C 11 C 12 N 13 P 14 P 15 C 16 C 17 N 18 P 19 P 20 P Abbreviations: C, complete; CG, cytogenetics; CG Dx,diagnosis based on CG data; CRCC,clear cell renal cell carcinoma; M-FISH, multifluor fluorescence in situ hybridization; N, no; OC, oncocytoma; P, partial; PRCC, papillary renal cell carcinoma; SNP Dx, diagnosis based on single-nucleotide polymorphism array data (virtual karyotype); UPD, uniparental disomy.
Do patients with maternal uniparental disomy for chromosome 7 have a distinct mild Silver-Russell phenotype?
By utilizing single nucleotide polymorphisms (SNPs) and non-polymorphic probes, the HumanCytoSNP-12 BeadChip can identify deletions, duplications, and uniparental disomy (UPD), or the receipt of two copies of a chromosome, or part of a chromosome, from one parent and no copies from the other parent.
Multiplex Percentages Causes of PWS PCR 60%-70% Deletion in paternally derived PWS region Yes 25%-30% Maternal uniparental disomy 15 (UPD) No <5% Chromosome translocation breaking within No the PWS critical region <5% Imprinting defect with variation No Methylation FISH Sequence Percentages MLPA PCR analysis analysis 60%-70% Yes Yes Yes No 25%-30% Yes Yes No No <5% No No Yes No <5% No No No Yes
Hemizygosity of the region containing the G365R site resulting from a large deletion, an inversion, uniparental disomy (genomic imprinting), or a de novo mutation may explain the pedigree.
Both phenotypes have been observed in the setting of chromosome 15 uniparental disomy, in which an offspring inherits both chromosome 15 homologs from one parent and none from the other.
Two inherited developmental disorders, Prader-Willi syndrome and Angelman syndrome, are associated with large deletions, uniparental disomy or imprinting mutations of the SNRPN region.