G12276A

# **General Information**

| **Position** | **12276** | **Variant** | **m.12276G\>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.12276G\>A** variant in MT\-TL2 has been reported in 2 pedigrees. To date, 2 carriers have been reported. Reported mutation loads ranged from 0% to 50%, with a median of 3% overall; affected carriers showed mutation loads from 0% to 50%, with a median of 3%. In one affected carrier, a marked tissue\-specific difference was observed, with higher mutation loads in muscle (50%) and fibroblasts (6%) than in blood (less than 3%) and bone marrow (less than 3%). The main clinical manifestations among affected carriers included CPEO, mild exercise intolerance, chronic progressive bilateral ptosis, myopathy, and restricted extraocular eye movements.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 12276 | m.12276G\>A | G12276A\-F1 | Germany | Mild exercise intolerance, chronic progressive bilateral ptosis, restricted extraocular eye movements | ND | ND | 2004 | [15591266](https://pubmed.ncbi.nlm.nih.gov/15591266/) |  |
| 2 | 12276 | m.12276G\>A | G12276A\-F2 | Italy | CPEO, myopathy | ND | ND | 2005 | [15649400](https://pubmed.ncbi.nlm.nih.gov/15649400/) |  |

# **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 | 12276 | m.12276G\>A | G12276A\-F1 | G12276A\-F1\-P1 | Uninf | F | Y | Y | A | 28 | \<3% | 50% | / | 6% (F), \<3% (BM) | Mild exercise intolerance, chronic progressive bilateral ptosis, restricted extraocular eye movements |  |
| 2 | 12276 | m.12276G\>A | G12276A\-F2 | G12276A\-F2\-P1 | Uninf | M | Y | Y | A | 66 | 0 | 18% | / | 0% (F) | CPEO, myopathy |  |

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