G12315A

# **General Information**

| **Position** | **12315** | **Variant** | **m.12315G\>A** | **Locus** | **MT\-TL2** | **RNA** | **tRNA Leu (CUN)** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \- | **Heteroplasmy** | \+ | **mitoTIP** | Pathogenic | **Pathogenicity** | Cfrm \[LP] |

"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.12315G\>A** variant in MT\-TL2 has been reported in 4 pedigrees. To date, 4 carriers have been reported. Reported mutation loads ranged from 0% to 94%, with a median of 0% overall; affected carriers showed mutation loads from 0% to 94%, with a median of 0%. In one affected carrier, the mutation was undetectable in blood (0%) and fibroblasts (0%) but exceeded 20% in muscle (94%). In one affected carrier, the mutation was undetectable in urine (0%), fibroblasts (0%), hair (0%), and bone marrow (0%) but exceeded 20% in muscle (62%). Similar tissue\-specific differences were observed in 1 additional carriers. The main clinical manifestations among affected carriers included myopathy, encephalomyopathy, progressive external ophthalmoplegia, and ophthalmoplegia.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 12315 | m.12315G\>A | G12315A\-F1 | Canada | Encephalomyopathy | ND | ND | 1996 | [8923013](https://pubmed.ncbi.nlm.nih.gov/8923013/) |  |
| 2 | 12315 | m.12315G\>A | G12315A\-F2 | USA | Myopathy, ophthalmoplegia | 0 | 0 | 2002 | [12398839](https://pubmed.ncbi.nlm.nih.gov/12398839/) |  |
| 3 | 12315 | m.12315G\>A | G12315A\-F3 | Italy | Progressive external ophthalmoplegia, myopathy | ND | ND | 2009 | [18977334](https://pubmed.ncbi.nlm.nih.gov/18977334/) |  |
| 4 | 12315 | m.12315G\>A | G12315A\-F4 | UK | Myopathy | ND | ND | 2009 | [19718780](https://pubmed.ncbi.nlm.nih.gov/19718780/) |  |

# **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 | 12315 | m.12315G\>A | G12315A\-F1 | G12315A\-F1\-P1 | Uninf | M | Y | Y | A | 54 | 0 | 94% | / | 0% (F) | Encephalomyopathy |  |
| 2 | 12315 | m.12315G\>A | G12315A\-F2 | G12315A\-F2\-Ⅱ1 | De novo | F | Y | Y | A | 17 | 17% | 62% | 0 | 0% (F), 0% (H), 0% (BM) | Myopathy, ophthalmoplegia |  |
| 3 | 12315 | m.12315G\>A | G12315A\-F3 | G12315A\-F3\-P1 | Uninf | ND | Y | Y | ND | 48 | / | / | / | / | Progressive external ophthalmoplegia, myopathy |  |
| 4 | 12315 | m.12315G\>A | G12315A\-F4 | G12315A\-F4\-P1 | Uninf | F | Y | Y | A | 53 | 0 | 88% | / | / | Myopathy |  |

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