A further case of familial ring chromosome 20 mosaicism - molecular characterization of the ring and review of the literature
- Resource Type
- Authors
- Johannes Zschocke; Ulrich A. Schatz; Birgit Krabichler; Harald Schober; Judith Dobesberger; Claudia Lamina; Dieter Kotzot; Iris Unterberger; Gerhard Luef; Christine Fauth
- Source
- European journal of medical genetics. 62(11)
- Subject
- 0301 basic medicine
Adult
Male
Mother to child transmission
Adolescent
Ring chromosome
Chromosomes, Human, Pair 20
Ring chromosome 20
030105 genetics & heredity
Biology
Ring (chemistry)
03 medical and health sciences
Young Adult
Genetics
medicine
Humans
Ring Chromosomes
Age of Onset
Child
Genetics (clinical)
In Situ Hybridization, Fluorescence
Epilepsy
Mosaicism
Chromosome
General Medicine
medicine.disease
Uniparental disomy
Infectious Disease Transmission, Vertical
SNP genotyping
Telomere
030104 developmental biology
Phenotype
Female
- Language
- ISSN
- 1878-0849
Ring chromosome 20 syndrome is a rare chromosomal disorder characterized by childhood-onset drug-resistant epilepsy, behavioral problems and variable cognitive impairment. While most cases occur sporadically, parent-to-child transmission of ring 20 mosaicism has only been reported in a few exceptional families. We identified a further family with mother-to-child transmission of ring 20 mosaicism. Detailed characterization of the ring chromosome showed a complete ring with preserved telomere repetitive sequences. SNP genotyping excluded mosaic uniparental disomy and indicated that the chromosome was transmitted without recombination from mother to child. These results corroborate the findings of a previous study and support the hypothesis that inherited mosaicism is due to transmission of an unstable chromosome either prone to ring opening or to ring re-formation.