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Mitochondrial nt3243 A>G Mutation in Taiwan

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02114554
Recruitment Status : Unknown
Verified April 2014 by National Taiwan University Hospital.
Recruitment status was:  Recruiting
First Posted : April 15, 2014
Last Update Posted : April 15, 2014
National Cheng-Kung University Hospital
Information provided by (Responsible Party):
National Taiwan University Hospital

Brief Summary:
Mitochondrial diseases are multisystem disorders that present with a wide range of clinical manifestations. Mitochondrial DNA nt3243A>G mutation is one of the most common mutations seen in mitochondrial diseases. Syndromes associated with this mutation include mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), maternally inherited diabetes and deafness (MIDD), myoclonic epilepsy with ragged red fibers (MERRF), and chronic progressive external ophthalmoplegia (CPEO). Clinical analyses of mitochondrial DNA nt3243A>G mutation from Taiwan remain scarce. The present study aims to investigate the clinical features and prognostic factors of patients with mt3243A>G mutation in Taiwan.

Condition or disease
MELAS Syndrome Noninsulin-dependent Diabetes Mellitus With Deafness

Detailed Description:

Patients and clinical features. The study will be carried out at National Taiwan University hospital, a tertiary medical center in Taipei. The Medical Genetics Department at National Taiwan University Hospital receives referral and conducts genetic testing for hospitals all around Taiwan. We will review the medical chart of all patients with documented mitochondrial DNA nt3243 point mutation. Demographic data, age at onset of symptoms, clinical features (including stroke, seizure-like episode, lactic level, diabetes mellitus, hearing impairment, myopathy, electrocardiogram abnormality, chronic progressive external ophthalmoplegia), relevant family history, treatment, and outcome will be recorded. Full MELAS phenotype was defined as the presence of focal central nervous system events, either seizures, strokes, or both.

Genetic analysis. Genomic DNA was extracted from peripheral blood leukocytes using the Puregene DNA purification kit (Gentra Systems, Minneapolis, Minnesota, USA). Polymerase chain reaction (PCR) for mitochondrial DNA nt3243 point mutation was carried out by left primer 5'-cggagtaatccaggtcggtt-3' and right primer 5'-ggaattgaacctctgactgt-3'. Presence of mitochondrial DNA nt3243 A>G mutation was detected after Hae III restriction enzyme digestion.

Heteroplasmy of mitochondrial nt3243A>G mutation was detected by real-time amplification refractory mutation system quantitative PCR (ARMS-qPCR) assay as previously reported [19]. In brief, wild-type and mutant-target primers, each 500 nM, were added into a 10-ml PCR reaction containing 1X KAPA SYBR® FAST ABI Prism® qPCR Master Mix (KAPABIOSYSTEMS, Cat No. KK4603) and 4 ng of genomic DNA. Real-time PCR conditions were 2 min at 50°C, 20 seconds at 95°C, followed by 40 cycles of 15 seconds of denaturation at 95°C and 30 seconds of annealing/extension at 62°C. Data of cross point and concentration fluorescent signal intensity of PCR products was recorded and analyzed by ABI StepOnePlusTM Real-Time PCR System (Applied Biosystems) and StepOne software v2.1 (Applied Biosystems). The threshold cycle ( CT value) within the linear exponential phase was used to construct the standard curve and to measure the original copy number of DNA template. The percentage of the mutant mtDNA was calculated using formula as below: Heteroplasmy %= 1/(1+ 1/2△CT).

Statistical analysis. SPSS 17.0 (SPSS, Chicago, IL, USA) was used for statistical analysis. Results were given as median and range, or mean ± 1 SD, when appropriate. Student 's t-test was used to compare unpaired groups. Fisher's exact test was used to determine associations between two categorical variables. Cox-regression model was used to analyze possible prognostic factors. Inter-group differences at outcome were compared by Kaplan-Meier estimate and log-rank test. Pearson's correlation was used to correlate heteroplasmy to age of diagnosis. A p value < 0.05 was considered statistically significant.

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Study Type : Observational
Estimated Enrollment : 40 participants
Observational Model: Case-Only
Time Perspective: Retrospective
Official Title: Clinical Characteristics and Prognostic Factors of Mitochondrial nt3243 A>G Mutation in Taiwan
Study Start Date : January 2014
Estimated Primary Completion Date : January 2015
Estimated Study Completion Date : January 2015

Primary Outcome Measures :
  1. Prognostic factors for poor outcome [ Time Frame: Within follow-up period, which is estimated to be 5 years in average. ]
    Poor outcome includes death and development of poor performance (a modified Rankin scale 4 or higher). Univariate and multivariate analyses will be utilized to study whether specific clinical presentations (for instance, the presence of stroke, seizure, diabetes, etc.) and degree of heteroplasmy are associated with poor outcome.

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients with mitochondrial DNA nt3243 A>G mutation detected at National Taiwan University Hospital.

Inclusion Criteria:

-Patients with mitochondrial DNA nt3243 A>G mutation

Exclusion Criteria:

-Patients without confirmed mitochondrial DNA nt3243 A>G mutation

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02114554

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Contact: Han-Chung Hsiue, MD 886-23123456 ext 66064

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National Taiwan University Hospital Recruiting
Taipei, Taiwan, 100
Contact: Han-Chung Hsiue, MD    886-23123456 ext 66064   
Principal Investigator: Pei-Lin Lee, MD, PhD         
Sub-Investigator: Ni-Chung Lee, MD, PhD         
Sponsors and Collaborators
National Taiwan University Hospital
National Cheng-Kung University Hospital
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Principal Investigator: Pei-Lin Lee, MD, PhD National Taiwan University Hospital

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Responsible Party: National Taiwan University Hospital Identifier: NCT02114554     History of Changes
Other Study ID Numbers: 201307058RINB
First Posted: April 15, 2014    Key Record Dates
Last Update Posted: April 15, 2014
Last Verified: April 2014

Keywords provided by National Taiwan University Hospital:

Additional relevant MeSH terms:
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Diabetes Mellitus
MELAS Syndrome
Diabetes Mellitus, Type 2
Mitochondrial Diseases
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hearing Loss
Hearing Disorders
Ear Diseases
Otorhinolaryngologic Diseases
Sensation Disorders
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Mitochondrial Encephalomyopathies
Mitochondrial Myopathies
Muscular Diseases
Musculoskeletal Diseases
Brain Diseases, Metabolic, Inborn
Brain Diseases, Metabolic
Brain Diseases
Central Nervous System Diseases
Cerebral Small Vessel Diseases
Cerebrovascular Disorders
Neuromuscular Diseases
Vascular Diseases
Cardiovascular Diseases
Metabolism, Inborn Errors