G4309A

# **General Information**

| **Position** | **4309** | **Variant** | **m.4309G\>A** | **Locus** | **MT\-TI** | **RNA** | **tRNA Ile** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \- | **Heteroplasmy** | \+ | **mitoTIP** | 64\.10% | **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.4309G\>A** variant in MT\-TI has been reported in 2 pedigrees. To date, 3 carriers have been reported. Reported mutation loads ranged from 0% to 70%, with a median of 11\.8% overall; affected carriers showed mutation loads from 0% to 70%, with a median of 16%; unaffected carriers showed mutation loads from 7\.5%, with a median of 7\.5%. In one affected carrier, the mutation was undetectable in blood (0%) but exceeded 20% in muscle (64\.5%). In one affected carrier, a marked tissue\-specific difference was observed, with higher mutation loads in muscle (70%) than in blood (16%). The main clinical manifestations among affected carriers included CPEO, deafness, and exercise intolerance.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 4309 | m.4309G\>A | G4309A\-F1 | Italy | CPEO | 3 | 0 | 1998 | [9808249](https://pubmed.ncbi.nlm.nih.gov/9808249/) |  |
| 2 | 4309 | m.4309G\>A | [G4309A\-F2](https://mitofam.com/doc/636/) | Spain | CPEO,exercise intolerance, deafness | 1 | 0 | 2002 | [11870684](https://pubmed.ncbi.nlm.nih.gov/11870684/) | Carrying A1555G |

# **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 | 4309 | m.4309G\>A | G4309A\-F1 | G4309A\-F1\-P1 | Uninf | F | Y | Y | A | 58 | 0 | 64\.5% | / | 1%(F) | CPEO |  |
| 2 | 4309 | m.4309G\>A | G4309A\-F2 | G4309A\-F2\-I2 | Uninf | F | N | N | A | ND | 7\.5% | / | / | / | Healthy | Carrying homo A1555G |
| 3 | 4309 | m.4309G\>A | G4309A\-F2 | G4309A\-F2\-II1 | Fam | F | Y | Y | A | 32 | 16% | 70% | / | / | CPEO,exercise intolerance, deafness | Carrying homo A1555G |

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