Mutational Analysis Of The MEF2C Gene In Xinjiang Uyghur Children With Simple Congenital Heart Disease

Objective: To perform the mutational analysis of the Myocyte enhancer factor 2C(MEF2C) gene in the Xinjiang Uyghur patient with congenital heart disease(CHD) and to provide new experimental evidence for further elucidate the molecular mechanism of congenital heart disease. Methods: A cohort of 200 unrealated subject with CHD and a total of 200 unrealated healthy individuals used as controls were recruited. The clinical datum were collected and the peripheral venous blood specimens were prepared. The genomic DNA was extracted from the peripheral blood lymphocytes, the entire coding exons of MEF2 C gene were amplified by polymerase chain reaction, and the amplicons were sequenced using the direct sequencing. The acquired sequences were aligned with those of MEF2 C publicized in GenBank by the aid of program BLAST to identify the sequence variations. Four of protein secondary structure prediction software were used for projections of MEF2 C gene. Multivariate unconditional Logistic regression analysis was preformed to study the risk factors of Uyghur CHD. Results:(1)Four noval heterrozygous mutations of MEF2 C were identified in 4 out of 200 unrelated Uyghur children with congenital heart diseases. And the other four new insert were discovered in the other four cases of Uyghur children with CHD. One is transition adenine(A) into guanine(G) at nucleotide 803 in MEF2 C gene( c.803A> G); It makes the 267’s leucine(leucine, L) into a proline(proline, P), p.L267 P mutation. One is transition guanine(G) into adenine(A) at nucleotide 809 in MEF2 C gene( c.809 G > A); It makes the 268’s serine(serine, S) into a phenylalanine(phenylalanine, F), p.S268 F mutation. One is transition adenine(A) into cytosine(C) at nucleotide 856 in MEF2 C gene( c.856 A> C). It makes the 296’s leucine at position 296(leucine, L) into glycine(glycine, G),p.L296 G mutation. the last is transition adenine(C) into cytosine(T) at nucleotide 871 in MEF2 C gene( c.871 C> T). It makes the 301’s valine(Valine, V) into leucine(leucine, L),p.V301 L mutation. Four new insert is the 134 s nucleotide sequence of MEF2 C encoding gene inserted into A, the 812 s nucleotide sequence of MEF2 C encoding gene inserted into A, the 836 s nucleotide sequence of MEF2 C encoding gene inserted into A, the 738 s nucleotide sequence of MEF2 C encoding gene inserted into G, The mutations were absent in the control individuals.(2)Prediction with SOPMA found that three point mutations(c.803A> G, c.809G> A, c.856A> C) can affect the gene contains α helix(h), extending chain(e), β angle(t) and trackless curl(c) ratio. Polyphen forecast found two point mutations(c.809G> A, c.871C> T) is likely to harm(possibly damaging) protein, two mutations(c.803A> G, c.856A> C) is useful possible damage(probably damaging) protein. We found four mutations may affect protein function.(3)Multivariate non-conditional Logistic regression analysis showed that mothers suffering from infectious diseases during early pregnancy, the mother trimester exposure to drugs or poisons and smoking is a risk factor for Uyghur with simple CHD(P<0.05).Conclusion: The study found that new mutations may associate with congenital heart disease, this will help to reveal new molecular etiology.