A8326G

# **General Information**

| **Position** | **8326** | **Variant** | **m.8326A\>G** | **Locus** | **MT\-TK** | **RNA** | **tRNA Lys** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \+ | **Heteroplasmy** | \+ | **mitoTIP** | 46\.20% | **Pathogenicity** | Reported |

"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.8326A\>G** variant in MT\-TK has been reported in 2 pedigrees. To date, 4 carriers have been reported. Homoplasmy was reported in 1/4 carriers (25%), and 2/4 carriers (50%) were affected. The main clinical manifestations among affected carriers included childhood\-onset myoclonus, proximal muscle weakness, acidosis, chronic cough, cystic fibrosis, headaches, hyperreflexia, increased deep tendon reflexes, and other features.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 8326 | m.8326A\>G | [A8326G\-F1](https://mitofam.com/doc/2180/) | United States | Mitochondrial cytopathy; myoclonus; cystic fibrosis comorbidity | 1 | 0 | 2002 | [12400067](https://pubmed.ncbi.nlm.nih.gov/12400067/) | / |
| 2 | 8326 | m.8326A\>G | [A8326G\-F2](https://mitofam.com/doc/2181/) | USA | Mitochondrial cytopathy / suspected mitochondrial disorder | 1 | 0 | 2002 | [12406974](https://pubmed.ncbi.nlm.nih.gov/12406974/) | / |

# **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 | 8326 | m.8326A\>G | A8326G\-F1 | A8326G\-F1\-II1 | Fam | F | N | N | A | ND | 89% | / | / | / | Asymptomatic for mitochondrial cytopathy; sinusitis and depression reported | Mother's blood DNA used as reference; A8326G about 89%. |
| 2 | 8326 | m.8326A\>G | A8326G\-F1 | A8326G\-F1\-III1 | Fam | F | Y | Y | A | 21 | near 100% | / | / | / | Childhood\-onset myoclonus; chronic cough; mild proximal weakness; hyperreflexia; cystic fibrosis | Also carries G15995A and CFTR DF508/R347P. |
| 3 | 8326 | m.8326A\>G | A8326G\-F2 | A8326G\-F2\-I1 | uninf | F | N | N | ND | ND | 89% | / | / | / | Healthy | A8326G 89% in blood/peripheral blood lymphocyte DNA; G15995A absent. |
| 4 | 8326 | m.8326A\>G | A8326G\-F2 | A8326G\-F2\-II1 | Fam | F | Y | Y | A | 21 | Homo | / | / | / | Proximal muscle weakness; increased deep tendon reflexes; progressive movement disorder with tremors involving trunk and face; headaches; stimulus\-sensitive myoclonus; acidosis | A8326G near\-homoplasmic/Homo in blood; co\-existing heteroplasmic G15995A in blood; exact A8326G percentage not reported. |

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