C12264T

# **General Information**

| **Position** | **12264** | **Variant** | **m.12264C\>T** | **Locus** | **MT\-TS2** | **RNA** | **tRNA Ser (AGY)** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \+ | **Heteroplasmy** | \+ | **mitoTIP** | 79\.30% | **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.12264C\>T** variant in MT\-TS2 has been reported in 2 pedigrees. To date, 11 carriers have been reported. Reported mutation loads ranged from 1% to 100%, with a median of 36% overall; affected carriers showed mutation loads from 34% to 100%, with a median of 97%; unaffected carriers showed mutation loads from 1% to 36%, with a median of 14\.5%. In one unaffected carrier, a marked tissue\-specific difference was observed, with higher mutation loads in bone marrow (18%) than in blood (1%). In one affected carrier, a marked tissue\-specific difference was observed, with higher mutation loads in muscle (100%) and bone marrow (100%) than in blood (34%). Similar tissue\-specific differences were observed in 1 additional carriers. The main clinical manifestations among affected carriers included cataract, myopathy, deafness, and developmental delay and epilepsy.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 12264 | m.12264C\>T | [C12264T\-F1](https://mitofam.com/doc/728/) | USA | Cataract | 8 | 0 | 2012 | [22369973](https://pubmed.ncbi.nlm.nih.gov/22369973/) |  |
| 2 | 12264 | m.12264C\>T | [C12264T\-F2 ](https://mitofam.com/doc/729/)| UK | Myopathy, deafness, developmental delay and epilepsy | 1 | 0 | 2012 | [22378285](https://pubmed.ncbi.nlm.nih.gov/22378285/) |  |

# **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 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-I2 | Uninf | F | N | N | A | ND | 1% | / | / | 18% (BM) | Healthy |  |
| 2 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-II2 | Fam | F | N | N | D | ND | / | / | / | / | Healthy |  |
| 3 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-II3 | Fam | M | N | N | A | ND | / | / | / | / | Healthy |  |
| 4 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-II4 | Fam | F | N | N | A | ND | / | / | / | / | Healthy |  |
| 5 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-II5 | Fam | M | N | N | A | ND | / | / | / | / | Healthy |  |
| 6 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-III1 | Fam | M | N | N | A | ND | / | / | / | / | Healthy |  |
| 7 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-III2 | Fam | M | Y | Y | A | 19 | 34% | 1 | / | 100% (BM) | Cataract |  |
| 8 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-III4 | Fam | F | N | N | A | ND | / | / | / | / | Healthy |  |
| 9 | 12264 | m.12264C\>T | C12264T\-F1 | C12264T\-F1\-III5 | Fam | M | N | N | A | ND | / | / | / | / | Healthy |  |
| 10 | 12264 | m.12264C\>T | C12264T\-F2 | C12264T\-F2\-I2 | Uninf | F | N | N | A | ND | 9% | 36% | 31% | 11% (F) | Healthy |  |
| 11 | 12264 | m.12264C\>T | C12264T\-F2 | C12264T\-F2\-II1 | Fam | F | Y | Y | A | 13 | 95% | 99% | 97% | 93% (F) | Myopathy, deafness, developmental delay and epilepsy |  |

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