Paediatric or syndromic cardiomyopathy

Gene: MT-TV

After NHS Genomic Medicine Service consideration, the rating of this gene has not been changed and remains amber. The reviewers note that cardiomyopathy is not the primary presenting feature. An alternative test is more suitable for syndromic mitochondrial disease: R300 Possible mitochondrial disorder - whole mitochondrial genome sequencing.

Created: 11 Mar 2026, 2:06 p.m. | Last Modified: 11 Mar 2026, 2:06 p.m.

Panel Version: 7.98

Green List (high evidence)

Comment on list classification: As reviewed by Katherine Schon on R131 Hypertrophic cardiomyopathy panel, HCM is reported as one of the presenting phenotypes in at least three unrelated patients with variants in MT-TV gene.

Expert opinion is sought from the Genomic Medicine Service on the inclusion of this gene on this panel with green raring in the next GMS update.

Created: 27 Jun 2025, 10:41 a.m. | Last Modified: 3 Nov 2025, 5:36 p.m.

Panel Version: 7.92

PMID:15320572 - The m.1644G>A variant in MT-TV gene has been reported in a patient with severe hypertrophic cardiomyopathy associated with MELAS. The familial phenotype included hypertrophic cardiomyopathy and MELAS, clinically mild cardiac hypertrophy, and deafness.

PMID:21986556 - Two patients were identified with variants in MT-TV gene (one with m.1628C>T variant and the other with m.1644G>A variant) by a systematic search in a series of patients suspected of mitochondrial cardiomyopathy. The patient with m.1628C>T variant had mild hypertrophic cardiomyopathy as one of the clinical presentations, while the other patient had pronounced cardiomegaly and biventricular hypertrophy.

PMID:34298071 - This study reported 223 paediatric mitochondria disease patients with confirmed genetic diagnosis, of which one patient had m.1644G>A variant. The patient had hypertrophic cardiomyopathy.

Created: 27 Jun 2025, 10:34 a.m. | Last Modified: 27 Jun 2025, 10:34 a.m.

Panel Version: 5.9

Mode of inheritance
MITOCHONDRIAL

Phenotypes
MELAS syndrome, MONDO:0010789; hypertrophic cardiomyopathy, MONDO:0005045

Publications

• 15320572
• 21986556
• 34298071

Green List (high evidence)

The m.1644G>A pathogenic variant has been associated with hypertrophic cardiomyopathy and c.1612C>T was also observed in an individual with hypertrophic cardiomyopathy (https://www.heartlungcirc.org/article/S1443-9506(22)00155-X/)

Created: 24 Jun 2025, 10:19 a.m. | Last Modified: 24 Jun 2025, 10:19 a.m.

Panel Version: 5.3

Mode of inheritance
MITOCHONDRIAL

Publications

• 34298071
• 15320572

Mode of pathogenicity
Other