G12283A

# **General Information**

| **Position** | **12283** | **Variant** | **m.12283G\>A** | **Locus** | **MT\-TL2** | **RNA** | **tRNA Leu (CUN)** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \- | **Heteroplasmy** | \+ | **mitoTIP** | 43\.20% | **Pathogenicity** | Reported \[VUS] |

"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.12283G\>A** variant in MT\-TL2 has been reported in 1 pedigree. To date, 1 carrier has been reported. Reported mutation loads ranged from 0% to 18%, with a median of 2% overall; affected carriers showed mutation loads from 0% to 18%, with a median of 2%. In one affected carrier, a marked tissue\-specific difference was observed, with higher mutation loads in muscle (18%) than in urine (4%). The main clinical manifestations among affected carriers included progressive bilateral ptosis, absent deep tendon reflexes, acute renal failure, bilateral pes cavus, chronic progressive external ophthalmoplegia, demyelinating polyneuropathy, drooping eyelids, generalized limb muscle atrophy, and other features.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 12283 | m.12283G\>A | G12283A\-F1 | UK | Neuromuscular disease | ND | ND | 2009 | [19853445](https://pubmed.ncbi.nlm.nih.gov/19853445/) |  |

# **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 | 12283 | m.12283G\>A | G12283A\-F1 | G12283A\-F1\-P1 | De novo | M | Y | Y | A | 31 | 0 | 18% | 4% | 0% (BM) | Progressive bilateral ptosis, chronic progressive external ophthalmoplegia, walking difficulty, poor motor skills in childhood, drooping eyelids, poor pen\-holding ability, demyelinating polyneuropathy, gout, acute renal failure, weak grip, leg weakness, gouty tophi, bilateral pes cavus, restricted eye movements, generalized limb muscle atrophy, reduced proximal and distal muscle power, absent deep tendon reflexes, impaired sensation above the ankles |  |

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