scholarly journals Patients With Extreme Early Onset Juvenile Huntington Disease Can Have Delays in Diagnosis: A Case Report and Literature Review

2021 ◽  
Vol 8 ◽  
pp. 2329048X2110361
Author(s):  
Ashley A. Moeller ◽  
Marcia V. Felker ◽  
Jennifer A. Brault ◽  
Laura C. Duncan ◽  
Rizwan Hamid ◽  
...  

Huntington disease (HD) is caused by a pathologic cytosine-adenine-guanine (CAG) trinucleotide repeat expansion in the HTT gene. Typical adult-onset disease occurs with a minimum of 40 repeats. With more than 60 CAG repeats, patients can have juvenile-onset disease (jHD), with symptom onset by the age of 20 years. We report a case of a boy with extreme early onset, paternally inherited jHD, with symptom onset between 18 and 24 months. He was found to have 250 to 350 CAG repeats, one of the largest repeat expansions published to date. At initial presentation, he had an ataxic gait, truncal titubation, and speech delay. Magnetic resonance imaging showed cerebellar atrophy. Over time, he continued to regress and became nonverbal, wheelchair-bound, gastrostomy-tube dependent, and increasingly rigid. His young age at presentation and the ethical concerns regarding HD testing in minors delayed his diagnosis.

2018 ◽  
Vol 48 (10) ◽  
pp. 1463-1471 ◽  
Author(s):  
Abderrahmane Hedjoudje ◽  
Gaël Nicolas ◽  
Alice Goldenberg ◽  
Catherine Vanhulle ◽  
Clémentine Dumant-Forrest ◽  
...  

2021 ◽  
Vol 33 (4) ◽  
pp. 293-300
Author(s):  
Larissa Arning ◽  
Huu Phuc Nguyen

Abstract The causative mutation for Huntington disease (HD), an expanded trinucleotide repeat sequence in the first exon of the huntingtin gene (HTT) is naturally polymorphic and inevitably associated with disease symptoms above 39 CAG repeats. Although symptomatic medical therapies for HD can improve the motor and non-motor symptoms for affected patients, these drugs do not stop the ongoing neurodegeneration and progression of the disease, which results in severe motor and cognitive disability and death. To date, there is still an urgent need for the development of effective disease‐modifying therapies to slow or even stop the progression of HD. The increasing ability to intervene directly at the roots of the disease, namely HTT transcription and translation of its mRNA, makes it necessary to understand the pathogenesis of HD as precisely as possible. In addition to the long-postulated toxicity of the polyglutamine-expanded mutant HTT protein, there is increasing evidence that the CAG repeat-containing RNA might also be directly involved in toxicity. Recent studies have identified cis- (DNA repair genes) and trans- (loss/duplication of CAA interruption) acting variants as major modifiers of age at onset (AO) and disease progression. More and more extensive data indicate that somatic instability functions as a driver for AO as well as disease progression and severity, not only in HD but also in other polyglutamine diseases. Thus, somatic expansions of repetitive DNA sequences may be essential to promote respective repeat lengths to reach a threshold leading to the overt neurodegenerative symptoms of trinucleotide diseases. These findings support somatic expansion as a potential therapeutic target in HD and related repeat expansion disorders.


2009 ◽  
Vol 149A (4) ◽  
pp. 598-601 ◽  
Author(s):  
Satoru Sakazume ◽  
Satoshi Yoshinari ◽  
Eiji Oguma ◽  
Emi Utsuno ◽  
Takuma Ishii ◽  
...  

Author(s):  
Jane S. Paulsen

Huntington disease (HD) is a autosomal dominant neurodegenerative disease caused by expansion of a trinucleotide repeat (cytosine, adenine, and guanine [CAG]) on the short arm of chromosome four. Average age of motor diagnosis is 39 years, and age at diagnosis is associated with the length of the CAG mutation. The prodrome of HD can be recognized 15 years prior to motor diagnosis and is characterized by subtle impairments in emotional recognition, smell identification, speed of processing, time estimation and production, and psychiatric abnormalities. HD shows particular vulnerability of the medium spiny neuron in the basal ganglia. Progressive brain dysfunction and neuron death lead to insidious loss of function in motor, cognitive, and behavioral control over 34 years (17 prodromal and 17 post-diagnosis). Treatment plans rely on genetic counseling, psychiatric symptom treatment as needed, physical therapy, and environmental modifications. There are two treatments for the reduction of chorea, but there are no disease-modifying therapies. Experimental therapeutics are rapidly emerging with multiple and various targets, however, and gene therapies to silence the mutant HD gene are currently ongoing. This chapter reviews clinical and neuropathological descriptions of HD and discusses potential underlying mechanisms and animal models, diagnostic and clinical assessments used to characterize and track the disease, treatment planning, and challenges for research to advance care.


2021 ◽  
Vol 141 (3) ◽  
pp. 399-413 ◽  
Author(s):  
R. A. Hickman ◽  
P. L. Faust ◽  
M. K. Rosenblum ◽  
K. Marder ◽  
M. F. Mehler ◽  
...  

AbstractNeuropathologic hallmarks of Huntington Disease (HD) include the progressive neurodegeneration of the striatum and the presence of Huntingtin (HTT) aggregates that result from abnormal polyQ expansion of the HTT gene. Whether the pathogenic trinucleotide repeat expansion of the HTT gene causes neurodevelopmental abnormalities has garnered attention in both murine and human studies; however, documentation of discrete malformations in autopsy brains of HD individuals has yet to be described. We retrospectively searched the New York Brain Bank (discovery cohort) and an independent cohort (validation cohort) to determine whether developmental malformations are more frequently detected in HD versus non-HD brains and to document their neuropathologic features. One-hundred and thirty HD and 1600 non-HD whole brains were included in the discovery cohort and 720 HD and 1989 non-HD half brains were assessed in the validation cohort. Cases with developmental malformations were found at 6.4–8.2 times greater frequency in HD than in non-HD brains (discovery cohort: OR 8.68, 95% CI 3.48–21.63, P=4.8 × 10-5; validation cohort: OR 6.50, 95% CI 1.83–23.17, P=0.0050). Periventricular nodular heterotopias (PNH) were the most frequent malformations and contained HTT and p62 aggregates analogous to the cortex, whereas cortical malformations with immature neuronal populations did not harbor such inclusions. HD individuals with malformations had heterozygous HTT CAG expansions between 40 and 52 repeats, were more frequently women, and all were asymmetric and focal, aside from one midline hypothalamic hamartoma. Using two independent brain bank cohorts, this large neuropathologic series demonstrates an increased occurrence of developmental malformations in HD brains. Since pathogenic HTT gene expansion is associated with genomic instability, one possible explanation is that neuronal precursors are more susceptible to somatic mutation of genes involved in cortical migration. Our findings further support emerging evidence that pathogenic trinucleotide repeat expansions of the HTT gene may impact neurodevelopment.


Neurogenetics ◽  
2021 ◽  
Author(s):  
Chiara Cavestro ◽  
Celeste Panteghini ◽  
Chiara Reale ◽  
Alessia Nasca ◽  
Silvia Fenu ◽  
...  

AbstractPLA2G6 is the causative gene for a group of autosomal recessive neurodegenerative disorders known as PLA2G6-associated neurodegeneration (PLAN). We present a case with early-onset parkinsonism, ataxia, cognitive decline, cerebellar atrophy, and brain iron accumulation. Sequencing of PLA2G6 coding regions identified only a heterozygous nonsense variant, but mRNA analysis revealed the presence of an aberrant transcript isoform due to a novel deep intronic variant (c.2035-274G > A) leading to activation of an intronic pseudo-exon. These results expand the genotypic spectrum of PLAN, showing the paramount importance of detecting possible pathogenic variants in deep intronic regions in undiagnosed patients.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Maria A. Gandini ◽  
Ivana A. Souza ◽  
Laurent Ferron ◽  
A. Micheil Innes ◽  
Gerald W. Zamponi

AbstractCACNA1A pathogenic variants have been linked to several neurological disorders including familial hemiplegic migraine and cerebellar conditions. More recently, de novo variants have been associated with severe early onset developmental encephalopathies. CACNA1A is highly expressed in the central nervous system and encodes the pore-forming CaVα1 subunit of P/Q-type (Cav2.1) calcium channels. We have previously identified a patient with a de novo missense mutation in CACNA1A (p.Y1384C), characterized by hemiplegic migraine, cerebellar atrophy and developmental delay. The mutation is located at the transmembrane S5 segment of the third domain. Functional analysis in two predominant splice variants of the neuronal Cav2.1 channel showed a significant loss of function in current density and changes in gating properties. Moreover, Y1384 variants exhibit differential splice variant-specific effects on recovery from inactivation. Finally, structural analysis revealed structural damage caused by the tyrosine substitution and changes in electrostatic potentials.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Paula Sienes Bailo ◽  
Raquel Lahoz ◽  
Juan Pelegrín Sánchez Marín ◽  
Silvia Izquierdo Álvarez

Abstract Background Despite the progress in the knowledge of Huntington disease (HD) in recent years, the epidemiology continues uncertain, so the study of incidence becomes relevant. This is important since various factors (type of population, diagnostic criteria, disease-modifying factors, etc.) make these data highly variable. Therefore, the genetic diagnosis of these patients is important, since it unequivocally allows the detection of new cases. Methods Descriptive retrospective study with 179 individuals. Incidence of HD was calculated from the ratio of number of symptomatic cases newly diagnosed per 100,000 inhabitants per year during the period 2007–2019 in Aragon (Spain). Results 50 (27.9%) incident cases of HD (CAG repeat length ≥ 36) were identified from a total of 179 persons studied. The remaining 129/179 (72.1%) were HD negative (CAG repeat length < 36). 29 (58.0%) females and 21 (42.0%) males were confirmed as HD cases. The overall incidence was 0.648 per 100,000 patient-years. 11/50 positive HD cases (22.0%) were identified by performing a predictive test, without clinical symptoms. The minimum number of CAG repeats found was 9 and the most common CAG length among HD negative individuals was 16. Conclusions Our incidence lied within the range reported for other Caucasian populations. Implementation of new techniques has allowed to determine the exact number of CAG repeats, which is especially important in patients with triplet expansions in an HD intermediate and/or incomplete penetrance allele, both in diagnostic, predictive and prenatal tests.


2004 ◽  
Vol 163 (12) ◽  
pp. 717-721 ◽  
Author(s):  
Sara Seneca ◽  
Dominique Fagnart ◽  
Kathelijn Keymolen ◽  
Willy Lissens ◽  
Daniele Hasaerts ◽  
...  

1999 ◽  
Vol 13 (4) ◽  
pp. 283-289 ◽  
Author(s):  
LC Williams ◽  
MR Hedge ◽  
G Herrera ◽  
PM Stapleton ◽  
DR Love

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