Mitochondrial Hearing Loss MTTS1 Gene

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MITOCHONDRIAL HEARING LOSS MTTS1 GENE

Gene Symbol: MT-TS1 (tRNA - Ser)

PSEUDONYMS: MTTS1

TURNAROUND TIME: 10 days

 TESTING METHODOLOGY: Polymerase chain reaction (PCR) and DNA Sequencing of the MT-TS1 gene on the mitochondrial genome.

SPECIMEN REQUIREMENTS:

  • Collect: Prefer two 5ml whole blood EDTA (lavender top) tube.
  • Min. Collection: 0.7 ml whole blood EDTA.
  • Transport: blood EDTA at Room Temp shipped regular next day air (No Saturday delivery; store specimen at 4°C and ship Monday).
  • Stability: Ambient: up to 7 days; Refrigerated: 2 weeks. Frozen: unacceptable
  • Unacceptable Conditions: Serum. Frozen or severely hemolyzed blood. Clotted blood.
  • Prenatal testing: Direct: 5ml direct unspun amniotic fluid or 15mg CVS tissue with a backup flask growing. Culture: confluent T25 flask. Maternal blood sample is required for maternal cell contamination studies.

A Molecular Genetics Laboratory Test Requisition must accompany the specimen. Contact the Molecular Laboratory at 918-502-1721 to obtain further information.

Note:
Counseling and informed consent are recommended for genetic testing; Center for Genetic Testing at Saint Francis consent form is available as a resource but not required.

INTERPRETATIVE DATA:

Incidence: Not well known and varies by ethnicity. May represent a small percentage of individuals with Non-Syndromic Hearing Loss (NSHL) that show no signs of Connexin 26 defects.
 
Inheritance: Maternal

Disease Characteristics: Moderate to profound child-onset NSHL. In some families the m.7445A>G substitution may also be associated with palmoplantar keratoderma

Molecular Genetic Mechanism: Several different disease causing mutations have been reported within the serine transfer RNA 1 gene. Those most often associated with NSHL include: m.7445A>C/G/T and m.7510T>C. Roughly 30% of cases of mitochondrial hearing loss are due to mutations in the MT-TS1 gene.

Related Tests: Mitochondrial Hearing Loss Panel, Mitochondrial Hearing Loss - m. A1555G Mutation

Clinical Sensitivity: 30%

Analytic Sensitivity: 99%

Test Limitations: Mutations present in less than 30% of the mitochondrial genomes may not be detected.

INDICATIONS FOR USE:

  • Moderate to profound hearing loss
  • Family history of hearing loss suggestive of maternal inheritance
  • Hearing loss with palmoplantar keratoderma
  • Known familial mutation within the MT-TS1 gene.

ADDITIONAL RESOURCES:

OMIM: www.omim.org/entry/590080
Gene Reviews: www.ncbi.nlm.nih.gov/books/NBK1422
Genetics Home Reference: www.ghr.nlm.nih.gov/gene/MT-TS1