A8344G

# **General Information**

| **Position** | **8344** | **Variant** | **m.8344A\>G** | **Locus** | **MT\-TK** | **RNA** | **tRNA Lys** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \- | **Heteroplasmy** | \+ | **mitoTIP** | Pathogenic | **Pathogenicity** | Cfrm \[P] |

"Pathogenicity" status is derived from published literature or predictions from bioinformatics tools. Researchers and clinicians are cautioned that additional data and/or analysis may still be necessary to confirm the pathological significance of these variants. For more information, please see [Mitofam Info](https://mitofam.com/doc/385/).

# **Pedigree Information**

The **m.8344A\>G** variant in MT\-TK has been reported in 2 pedigrees. To date, 2 carriers have been reported. Reported mutation loads ranged from 2\.1% to 52%, with a median of 27\.1% overall; affected carriers showed mutation loads from 2\.1% to 52%, with a median of 27\.1%. The main clinical manifestations among affected carriers included MERRF, seizures, and chronic respiratory failure.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 8344 | m.8344A\>G | A8344G\-F1 | United States | Seizures | 0 | 0 | 2022 | [34969639](https://pubmed.ncbi.nlm.nih.gov/34969639/) | Table 1 case 24 |
| 2 | 8344 | m.8344A\>G | A8344G\-F2 | United States | MERRF; chronic respiratory failure | 0 | 0 | 2022 | [34969639](https://pubmed.ncbi.nlm.nih.gov/34969639/) | Table 1 case 25 |

# **Carrier Information**

| **No.** | **Position** | **Variant** | **Family ID** | **Carrier ID** | **Type (Fam/De novo/Uninf)** | **Gender (F/M)** | **Proband (Y/N)** | **Affected (Y/N)** | **Die/Alive(D/A)** | **Age** | **Blood Mutant Level** | **Muscle Mutant level** | **Urine Mutant level** | **Other Mutant level** | **Clinical Features** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 8344 | m.8344A\>G | A8344G\-F1 | A8344G\-F1\-P24 | Uninf | ND | Y | Y | ND | 0\.3 | / | / | / | 2\.1% (Saliva) | Seizures | Table 1 case 24; maternal testing ND; WES nondiagnostic. |
| 2 | 8344 | m.8344A\>G | A8344G\-F2 | A8344G\-F2\-P25 | Uninf | ND | Y | Y | ND | 29 | 52% | / | / | / | MERRF; chronic respiratory failure | Table 1 case 25; maternal testing ND. |

For abbreviations and other usage instructions, please see [Mitofam Info](https://mitofam.com/doc/385/).