J Med Cases

Journal of Medical Cases, ISSN 1923-4155 print, 1923-4163 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Med Cases and Elmer Press Inc

Journal website https://www.journalmc.org

Case Report

Volume 12, Number 11, November 2021, pages 455-459

Dilated Cardiomyopathy due to the Novel MT-CYB Missense Mutation m.14757T>C

Figure

Figure 1. Upper panel: (a) muscle biopsy section stained for Gomori’s trichrome shows muscle fibers with normal distribution of mitochondria (magnification × 40). (b) Succinate dehydrogenase (SDH) staining shows a similar picture with some low dark blue fibers (magnification × 40) compared to a healthy control (c). Lower panel: automated sequence analysis of the region encompassing the m.14757T>C mutation of the proband’s mtDNA in muscle.

Tables

**Table 1.** Activities of Respiratory Chain Enzymes in the Muscle Extract of the Described Patient
Enzymes	Patient	Controls
Patient values are expressed in nmol/min/mg. SDH: succinate dehydrogenase; NADH: ubiquinone oxidoreductase.
Complex-I	30	19 - 43
Complex-III	51	91 - 161
Complex-II + III	13	14 - 30
Complex-IV	40	34 - 80
Citrate synthase	125	101 - 225
SDH	28	20 - 38
NADH dehydrogenase	170	209 - 383

**Table 2.** Prediction Data of Mutations Detected in the Index Patient
Mutation	AA₁	Prediction	Available data	Prediction basis	Substitution effect	Prediction data
AA: amino acid; PSIC: position-specific independent counts; PHAT: predicted hydrophobic and transmembrane matrix.
M4T	Medium	Possibly damaging	Alignment structure	Structure	1.1.1: structural effect, buried site, hydrophobicity change at buried site	PSIC score difference: 0.810. Normed accessibility: 0.13. Hydrophobicity change: 0.77
T194A		Benign	Alignement	Sequence annotation	N/A	PHAT matrix element difference: 0