Clinical Study Of Phenotypic Differences In Familial Hypertrophic Cardiomyopathy

Objective: To analyze the differences in disease phenotypes and genetic mutations carried in a family of hypertrophic cardiomyopathy(HCM).Methods: One HCM family and 30 normal subjects were selected as the control group.All subjects underwent two-dimensional echocardiography and 2D-STI analysis.The end-diastolic thickness,left atrial anterior and posterior diameter(LA),and left atrial anterior-posterior diameter(LA)of each wall of 17 segments of the heart were measured.Right atrium anteroposterior diameter(RA),left atrial volume(LAV),left atrial volume index(LAVI),left ventricular myocardial mass index(LVMI),left ventricular wall relative thickness(RWT),left ventricular end-diastolic diameter(LVDd),Left ventricular end-systolic diameter(LVDs),left ventricular ejection fraction(LVEF),early mitral valve diastolic blood flow velocity(E),late mitral valve diastolic blood flow velocity(A),early mitral valve diastole and diastole Late blood flow velocity ratio(E/A),tissue Doppler mitral valve annulus sidewall velocity(e`sidewall),tissue Doppler mitral valve annulus ventricular septal velocity(e`interval),two The ratio of the E wave velocity of the cusp orifice to the tissue Doppler mitral valve annulus velocity e`(E/e`),the peak flow velocity of tricuspid regurgitation,the maximum pressure difference,and the left ventricular outflow tract pressure difference(LAOT-PG),global longitudinal strain(GLS),global circumferential strain(GCS);laboratory serum BNP examination and whole exome gene sequencing for HCM patients in the family.Results: Compared with the control group,IVDS,RWT,E/A,MV-E/e’,LAV,and LAVI all increased;MV-A,MV-e’ sidewall MV-e’ interval and GLS were all decreased,and the difference was statistically significant(P<0.05);the two HCM patients in this family showed early age of onset,severe myocardial hypertrophy,and diastolic dysfunction,and both showed electrocardiogram.It is a non-specific ST-T change,but the two patients have different clinical manifestations.Different parts of myocardial hypertrophy lead to left ventricular outflow tract(LVOT)hemodynamics with obstructive and non-obstructive,and non-obstructive The members of Ⅱ have more severe heart failure than the members of the obstructive type;gene sequencing revealed that both Ⅱ-1and Ⅱ-2 carry the MYH7-G768 R and RYR2-L4078 I gene mutations,and Ⅱ-2 also carries the AKAP9-I1861 V gene mutation.Conclusion: The disease phenotypes of patients with the same HCM pathogenic gene mutations in this family are similar but not completely the same,and there are differences in clinical symptoms,cardiac function and morphological manifestations.HCM disease phenotypes in the same family under the same genetic background Differences can better explain the heterogeneity of HCM.Family members also carry different mutations in other genes,suggesting that modified genes may be an influencing factor of HCM heterogeneity,and comprehensive genetic screening of HCM patients is necessary.