T5543C

# General Information

| **Position** | **5543** | **Variant** | **M.5543T\>C** | **Locus** | **MT\-TW** | **RNA** | **TRNA Trp** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \- | **Heteroplasmy** | \+ | **MitoTIP** | 47\.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.5543T\>C** variant in MT\-TW has been reported in 2 pedigrees. To date, 3 carriers have been reported. Reported mutation loads ranged from 0% to 99%, with a median of 29% overall; affected carriers showed mutation loads from 0% to 99%, with a median of 48\.5%; unaffected carriers showed mutation loads from 8% to 29%, with a median of 14%. In one affected carrier, the mutation was undetectable in blood (0%) but exceeded 20% in muscle (95%). In one affected carrier, a marked tissue\-specific difference was observed, with higher mutation loads in muscle (99%) and urine (92%) than in blood (42%). Similar tissue\-specific differences were observed in 1 additional carriers. The main clinical manifestations among affected carriers included headaches, mitochondrial myopathy, and hemianopia persisted.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 5543 | M.5543T\>C | T5543C\-F1 | USA | Mitochondrial myopathy | 1 | 1 | 2005 | [15670724](https://pubmed.ncbi.nlm.nih.gov/15670724/) |  |
| 2 | 5543 | M.5543T\>C | [T5543C\-F2 ](https://mitofam.com/doc/880/)| Pakistani | MELAS | 3 | 1 | 2011 | [21712854](https://pubmed.ncbi.nlm.nih.gov/21712854/) |  |

# 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 | 5543 | M.5543T\>C | T5543C\-F1 | T5543C\-F1\-P1 | De novo | M | Y | Y | ND | 58 | 0 | 95% | / | 4%, 7%, Trace (H roots); trace (buccal) | Mitochondrial myopathy |  |
| 2 | 5543 | M.5543T\>C | T5543C\-F2 | T5543C\-F2\-III1 | Uninf | F | Y | Y | ND | ND | 42% | 99% | 92% | 55% (BM) | Headaches,hemianopia persisted |  |
| 3 | 5543 | M.5543T\>C | T5543C\-F2 | T5543C\-F2\-II4 | Uninf | F | N | N | ND | ND | 8% | / | 29% | 14%(BM) | Healthy |  |

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