Inborn Error Metabolism (IEM) Screening, Blood Spot Test Report: Normal profile
PTH (1-84): 3.8 pmol/L (Normal range 1.6 - 6.0)
The pediatrician proceeded with a lumbar puncture. The lactate level for the CSF sample was 9.28 mmol/L (normal reference range 0.50 - 2.20). Culture and Sensitivity of CSF: No growth.
PCR and Direct Sequencing of MT-TL1 tRNA gene
DNA change: m.3243A>G
Approximately 70% heteroplasmy
Classification: Pathogenic
Interpretation/Comment:
The MT-TL1: m.3243A>G mutation was detected at approximately 70% of heteroplasmy in his blood-derived DNA sample.
The mutation is maternally inherited, therefore there is NO risk of transmitting the mutation to any children he may have in future.
Testing should be offered to appropriate maternal relatives as they are at risk of inheriting the MT-TL1: m.3243A>G mutation and developing associated symptoms.
Recommend referral to Clinical Geneticist