T8851C

# **General Information**

| **Position** | **8851** | **Variant** | **m.8851T\>C** | **Locus** | **MT\-ATP6** | **Amino\-AcidChange** | **W109R** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \+ | **Heteroplasmy** | \+ | **APOGEE2** | Likely\-pathogenic | **Pathogenicity** | Cfrm \[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.8851T\>C** variant in MT\-ATP6 has been reported in 1 pedigree. To date, 3 carriers have been reported. Reported mutation loads ranged from 52% to 97%, with a median of 87% overall; affected carriers showed mutation loads from 68% to 97%, with a median of 92%; unaffected carriers showed mutation loads from 52% to 60%, with a median of 56%. The main clinical manifestations among affected carriers included failure to thrive, leigh syndrome, peripheral neuropathy and muscle weakness since age 22, ataxia, hypotonia, microcephaly, and psychomotor retardation.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 8851 | m.8851T\>C | [T8851C\-F1](https://mitofam.com/doc/1781/) | Czech Republic | Leigh syndrome; mitochondrial disease | 1 | 1 | 2013 | [23206802](https://pubmed.ncbi.nlm.nih.gov/23206802/) |  |

# **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 | 8851 | m.8851T\>C | T8851C\-F1 | T8851C\-F1\-II2 | Fam | F | N | N | A | 20 | 60% | / | / | 52%(BM) | Healthy |  |
| 2 | 8851 | m.8851T\>C | T8851C\-F1 | T8851C\-F1\-II1 | Fam | F | Y | Y | A | 3 | 92% | 97% | 87% | 95%(H); 92%(BM) | Failure to thrive; microcephaly; psychomotor retardation; hypotonia; ataxia; Leigh syndrome |  |
| 3 | 8851 | m.8851T\>C | T8851C\-F1 | T8851C\-F1\-I2 | Uninf | F | N | Y | A | 36 | 68% | / | 69% | 85%(BM); 96%(H) | Peripheral neuropathy and muscle weakness since age 22 |  |

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