"Compensatory" uniparental disomy of chromosome 21 in two cases.

"Compensatory" uniparental disomy of chromosome 21 in two cases.

Two cases of growth failure, microcephaly, facial dysmorphism, muscular hypertonia, and severe psychomotor retardation are described. At birth, both cases had cytogenetic mosaicism in lymphocytes and skin fibroblasts, in case 1 ring chromosome 21 and monosomy 21 and in case 2, deletion of chromosome 21 and monosomy 21. At a later age the lymphocyte karyotype changed almost completely to 46,XX, ...

Maternal Uniparental Disomy of Human Chromosome 7

Maternal uniparental disomy for chromosome 14.

We report the first case of maternal uniparental disomy of chromosome 14 in humans. The male proband inherited a balanced 13;14 Robertsonian translocation from his mother. Molecular studies showed that neither chromosome 14 was of paternal origin. The proband is of above average intelligence, but he has hydrocephalus, a bifid uvula, premature puberty, short stature, and small testes. It is not ...

Somatic uniparental disomy of Chromosome 16p in hemimegalencephaly

Hemimegalencephaly (HME) is a heterogeneous cortical malformation characterized by enlargement of one cerebral hemisphere. Somatic variants in mammalian target of rapamycin (mTOR) regulatory genes have been implicated in some HME cases; however, ∼70% have no identified genetic etiology. Here, we screened two HME patients to identify disease-causing somatic variants. DNA from leukocytes, buccal ...

Epigenetic detection of human chromosome 14 uniparental disomy.

The recent demonstration of genomic imprinting of DLK1 and MEG3 on human chromosome 14q32 indicates that these genes might contribute to the discordant phenotypes associated with uniparental disomy (UPD) of chromosome 14. Regulation of imprinted expression of DLK1 and MEG3 involves a differentially methylated region (DMR) that encompasses the MEG3 promoter. We exploited the normal differential ...