1. No increase in the CTG repeat size during transmission from parent with expanded allele: false suspicion of contraction phenomenon.
- Author
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Goñi Ros N, Sienes Bailo P, González Tarancón R, Martorell Sampol L, and Izquierdo Álvarez S
- Abstract
Objectives: Myotonic dystrophy type 1 (DM1), also known as Steinert's disease, is a chronic, progressive and disabling multisystemic disorder with a broad spectrum of severity that arises from an autosomal-dominant expansion of the Cytosine-Thymine-Guanine (CTG) triplet repeat in the 3' untranslated region of the DMPK gene (19q13.3)., Case Presentation: In this study, we report the case of a family with several intergenerational expansions of the CTG repeat, with an additional case of a false suspicion of contraction phenomenon due to TP-PCR limitations., Conclusions: The meiotic instability of the (CTG)
n repeats leads to genetic anticipation where increased size of DM1 mutation and a more severe phenotype have been reported in affected individuals across generations. Even if extremely rare, a decrease in the CTG repeat size during transmission from parents to child can also occur, most frequently during paternal transmissions., Competing Interests: Competing interests: Authors state no conflict of interest., (© 2023 the author(s), published by De Gruyter, Berlin/Boston.)- Published
- 2023
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