Chromosome 14 uniparental disomy syndrome. Uniparental disomy (UPD) of chromosome 14.
Incidence
Seems rare. Since 1991, 29 of the 47 possible uniparental disomies have been identified among individuals ascertained for medical reasons. The inheritance of both homologues from one parent is uniparental heterodisomy and inheritance from one parent is uniparental isodisomy. The inheritance from the mother is known as maternal uniparental disomy (mUPD). UPD is a case of abnormal phenotype due to homozygosity for recessive alleles and parental imprinting of genes. Formation of de novo robersonian translocation is involved in UPD.
Clinical Characteristics
Uniparental disomy (UPD) is the presence, in a diploid individual, of a chromosome pair that derives from only one parent. In 1991, the first clinical case of UPD was reported and involved a girl with cystic fibrosis and unusually short stature who carried two copies of maternal chromosome 7. Since 1991, 29 of the 47 possible uniparental disomies have been identified among individuals ascertained for medical reasons. In summary, it is related to the presence of two homologues derived from one parent in a diploid offspring. Hydrocephalus, delayed development, small hands, and hyperextensible joints are the main features. Cases in which two homologues are derived from the mother are known as maternal uniparental disomy (mUPD) syndrome.
Precipitants
None
Provocation Tests
None
Diagnostic Procedures
Karyotype. Disotomy of 14 chromosome.