De novo Huntington′s disease due to paternal intermediate alleles: a case report and literature review
10.3760/cma.j.cn113694-20230131-00058
- VernacularTitle:父源性中间突变致新发亨廷顿病1例并文献复习
- Author:
Anqi HUANG
1
;
Shanshan MEI
;
Yan HAN
;
Xixi YANG
;
Lili CUI
;
Suobin WANG
;
Huiqing DONG
;
Cunjiang LI
;
Hua LIN
Author Information
1. 首都医科大学宣武医院神经内科，北京100053
- Keywords:
Huntington disease;
Trinucleotide repeat expansion;
Intermediate alleles;
Involuntary movement;
HTT gene
- From:
Chinese Journal of Neurology
2023;56(9):992-1000
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To report the clinical manifestation and genetic characteristics of a case of de novo Huntington′s disease due to paternal intermediate alleles. Methods:Clinical data and imaging features of a middle-aged female, who complained of unstable walking without positive family history and was admitted to Xuanwu Hospital, Capital Medical University on September 20, 2022, were retrospectively analyzed. The serum samples of the patient and her parents were used to screen HTT gene dynamic mutation in accordance with the principle of informed consent and voluntary. And the relevant literatures were reviewed. Results:This is a 38-year-old female with progressive course, who presented as ataxia, involuntary movement at the end of extremities, dystonia, and cognitive impairment. Imaging results showed atrophy of bilateral caudate nuclei, as well as decreased glucose metabolism of bilateral caudate nuclei, putamen and partial cortex. Genetic testing showed the abnormal expansion of polymorphic trinucleotide (CAG) repeats in HTT gene and confirmed the diagnosis of Huntington′s disease. The CAG repeat length of the patient was 17/47 (pathopoiesis), of the father was 17/35 (intermediate alleles), and of the mother was 17/17 (normal). Conclusions:Paternal intermediate alleles may cause the first case of Huntington′s disease in a family. Importantly, HTT gene screening should be performed for the patient and parents when the diagnosis of Huntington′s disease is clinically possible despite negative family history, to prevent the misdiagnosis.
