C3340T

# **General Information**

| **Position** | **3340** | **Variant** | **m.3340C\>T** | **Locus** | **MT\-ND1** | **Amino\-AcidChange** | **P12S** |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Homoplasmy** | \+ | **Heteroplasmy** | \- | **APOGEE2** | VUS\- | **Pathogenicity** | Reported |

"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.3340C\>T** variant in MT\-ND1 has been reported in 1 pedigree. To date, 3 carriers have been reported. Reported mutation loads ranged from 30% to 40%, with a median of 30% overall; affected carriers showed mutation loads from 30%, with a median of 30%; unaffected carriers showed mutation loads from 30% to 40%, with a median of 35%. The main clinical manifestations among affected carriers included generalized hypotonia, leukoencephalopathy, and nystagmus.

| **No.** | **Position** | **Variant** | **Family ID** | **Nationality** | **Diseases** | **Unaffected Maternal Relatives** | **Affected Maternal Relatives** | **Publication Year** | **PMID/Ref** | **Note** |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 3340 | m.3340C\>T | C3340T\-F1 | Italy | nystagmus,generalized hypotonia,leukoencephalopathy | 2 | 0 | 2004 | [15465027](https://pubmed.ncbi.nlm.nih.gov/15465027/) | carrying 3158 ins T,T6719C,A8803T |

# **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 | 3340 | m.3340C\>T | C3340T\-F1 | C3340T\-F1\-I1 | Uninf | F | N | N | A | ND | 30% | / | / | / | healthy |  |
| 2 | 3340 | m.3340C\>T | C3340T\-F1 | C3340T\-F1\-II1 | Fam | F | Y | Y | A | 32 | 30% | 30% | / | / | nystagmus,generalized hypotonia,leukoencephalopathy | carrying 3158 ins T,T6719C,A8803T |
| 3 | 3340 | m.3340C\>T | C3340T\-F1 | C3340T\-F1\-II2 | Fam | F | N | N | A | ND | 40% | / | / | / | healthy |  |

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