DNA methylation and triplet repeat stability: New proposals addressing actual questions on the CGG repeat of fragile X syndrome

Journal Article · Fri Aug 09 04:00:00 EDT 1996 · American Journal of Medical Genetics

DOI:https://doi.org/10.1002/ajmg.1320640202· OSTI ID:478877

Woehrle, D; Schwemmle, S; Steinbach, P ^[1]

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1. Univ. of Ulm (Germany)

Methylation of expanded CGG repeats in the FMR1 gene may well have different consequences. One is that methylation, extending into upstream regulatory elements, could lead to gene inactivation. Another effect of methylation, which we have obtained evidence for, could be stabilization of the repeat sequence and even prevention of premutations from expansion to full mutation. The full mutation of the fragile X syndrome probably occurs in an early transitional stage of embryonic development. The substrate is a maternally inherited premutation. The product usually is a mosaic pattern of full mutations detectable in early fetal life. These full mutation patterns are mitotically stable as, for instance, different somatic tissues of full mutation fetuses show identical mutation patterns. This raised the following questions: What triggers repeat expansion in that particular stage of development and what causes subsequent mitotic stability of expanded repeats? 21 refs., 1 fig.

• Sponsoring Organization: USDOE
• OSTI ID: 478877
• Journal Information: American Journal of Medical Genetics, Journal Name: American Journal of Medical Genetics Journal Issue: 2 Vol. 64; ISSN 0148-7299; ISSN AJMGDA
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
CHROMOSOMAL ABERRATIONS
DNA SEQUENCING
FETUSES
GENE MUTATIONS
GENES
GENETIC MAPPING
GENETICS
HEREDITARY DISEASES
HUMAN X CHROMOSOME
INSTABILITY
MENTAL DISORDERS
METHYLATION
MITOSIS
MOSAICISM
MUTATIONS
NUCLEOTIDES
ONTOGENESIS
SEX DEPENDENCE