T3291C-F4

**Figure 1\. Pedigree diagram for family T3291C\-F4\.**

![](/media/202606/20260630210803897888.png)

# Pedigree Information

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 3291 | m.3291T\>C | T3291C\-F4 | Japan | Encephalomyopathy | 4 | 4 | 2011 | [21863273](https://pubmed.ncbi.nlm.nih.gov/21863273/) |  |

The **m.3291T\>C** variant in MT\-TL1 was reported in family T3291C\-F4 from Japan with encephalomyopathy. The pedigree record reported 4 unaffected and 4 affected maternal relatives, and the carrier table includes 9 listed carriers. Homoplasmy was reported in 0/9 listed carriers; 5/9 carriers were affected, and the main clinical manifestation among affected carriers was hearing loss, glaucoma, progressive bedridden state, progressive gait disturbance, bilateral hearing deficits, cataracts, mild external ophthalmoparesis, nystagmus.

# 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 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-I2 | Uninf | F | N | Y | D | 80 | / | / | / | / | Hearing loss, glaucoma, progressive bedridden state |  |
| 2 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-II1 | Fam | F | N | N | A | ND | / | / | / | / | Healthy |  |
| 3 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-II2 | Fam | F | N | N | A | ND | / | / | / | / | Healthy |  |
| 4 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-II4 | Fam | F | Y | Y | A | 45 | 11% | 74% | / | / | Progressive gait disturbance, bilateral hearing deficits, cataracts, glaucoma, mild external ophthalmoparesis, nystagmus, sensorineural hearing loss, dysarthria, severe cerebellar ataxia, mild proximal limb weakness, reduced tendon reflexes, diffuse paroxysmal slow activity induced by photo\-stimulation, low amplitude and short motor\-unit potential in proximal extremities, frontal lobe and cerebellar cortex atrophy, impaired intelligence, memory and frontal function |  |
| 5 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-II5 | Fam | M | N | N | A | ND | / | / | / | / | Healthy |  |
| 6 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-III2 | Fam | F | N | Y | A | 41 | / | / | / | / | Palindromic rheumatism, recurrent migraine |  |
| 7 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-III3 | Fam | F | N | Y | A | 36 | 16% | / | / | / | Photo\-induced myoclonus, negative myoclonus, absence of all limb tendon reflexes, mild truncal ataxia, cerebellar atrophy |  |
| 8 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-IV1 | Fam | F | N | Y | A | 15 | 27% | / | / | / | Loss of consciousness, myoclonic jerks, generalized seizure, absent tendon reflexes, and slight cognitive decline. |  |
| 9 | 3291 | m.3291T\>C | T3291C\-F4 | T3291C\-F4\-IV2 | Fam | M | N | N | A | ND | / | / | / | / | Healthy |  |

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