Maple syrup urine disease（枫糖尿症） |
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BCKDHA, BCKDHB, DBT 这三个基因的表达产物结合成一个多酶复合体，代谢食物中的支链氨基酸亮氨酸、异亮氨酸和缬氨酸。这3个基因中任何一个突变都会造成机体无法代谢上述氨基酸，这些氨基酸及其副产品在体内堆积，对大脑及身体器官造成损害。
BCKDHA基因编码BCKD（支链α-酮酸脱氢酶多酶复合体）的α亚基，2个α亚基和2个β亚基组成BCKD的一个E1单元。BCKDHA基因已发现40多种突变，多数在经典型枫糖尿症患者中发现。这些突变大多是点突变，常见的突变位点是Y438N。
| 基因名称 | 基因全名 | 基因位置 | 外显子个数 | CDS长度 |
|---|---|---|---|---|
| BCKDHA | branched chain keto acid dehydrogenase E1, alpha polypeptide | 19q13.1-q13.2 | 9 | 约1774 bp |
| 基因摘要 | The branched-chain alpha-keto acid (BCAA) dehydrogenase (BCKD) complex is an innter mitochondrial enzyme complex that catalyzes the second major step in the catabolism of the branched-chain amino acids leucine, isoleucine, and valine. The BCKD complex consists of three catalytic components: a heterotetrameric (alpha2-beta2) branched-chain alpha-keto acid decarboxylase (E1), a dihydrolipoyl transacylase (E2), and a dihydrolipoamide dehydrogenase (E3). This gene encodes the alpha subunit of the decarboxylase (E1) component. Mutations in this gene result in maple syrup urine disease, type IA. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Sep 2009]. | |||