Fig. 1

Family pedigree and clinical phenotypes. A. Pedigree of the consanguineous family affected by DCM inherited in an autosomal recessive pattern. square represents male and circle represents female. Grey square/circles represent healthy members without DCM. Black square/circles represent DCM patients. The proband is indicated by an arrow. Square/circles with slash sign represent deceased males/females. B. Echocardiography and electrocardiogram images of the proband showing dilated heart and decreased LVEF. Upper left panel: parasternal long-axis echocardiogram view of the left ventricle showing two-dimensional measurements of right and left ventricular wall thickness, septal thickness and right and left ventricular internal diameter. Upper right panel: apical four chamber echocardiogram view showing length, area, volume, end-systolic volume (ESV) and ejection fraction of the left ventricle. Lower panel: 12-lead electrocardiogram (ECG) showing paroxysmal sinus tachycardia and complete left bundle branch block. C. Candidate DCM variant in BICD2. Upper panel: the variant located in exon 7 of BICD2. Lower panel: location of the variant in the BICD2 protein 3D structure predicted by the AlphaFold algorithm. D. Sanger sequencing results indicating the genotypes of the family members. Arrows indicate the variant locus. E. Protein sequence alignment of the amino acid sequences surrounding the BICD2 variant with orthologues from H. sapiens to Danio rerio. Note that the amino acid sequences surrounding the affected amino acid residues are highly conserved