Diagnosis, treatment and genetic analysis of a child with infantile neuroaxonal dystrophy.

Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disease characterized by early hypotonia, and rapid progression to psychomotor development regression, pyramidal tract positivity, and spastic quadriplegia. In this report, we describe a Chinese patient with INAD who presented with hypotonia, delayed motor and language development, and subsequently improved with rehabilitation training. Genetic testing revealed that the patient had compound heterozygous PLA2G6 gene variants, with the heterozygous c.496dupG (p.Glu166fsTer32) variant inherited from her father and the heterozygous c.2189T>G (p.Met730Arg) variant inherited from her mother. The p.Met730Arg was a novel variant. The protein structure predicts that the structural stability of the mutant protein may change, and the in vivo experimental results show that the expression of the mutant protein decrease. This study enriches the PLA2G6 gene mutation spectrum, and improves the clinicians' diagnostic awareness of INAD.婴儿神经轴索营养不良(infantile neuroaxonal dystrophy，INAD)是一种罕见的常染色体隐性遗传神经退行性疾病，主要临床表现为早期肌张力降低，可快速进展为精神运动发育倒退、锥体束征阳性及痉挛型四肢瘫痪。本文报道1例中国INAD患儿，该患儿表现为肌张力降低，运动及语言发育迟缓，康复训练后得到改善。基因检测结果提示该患儿PLA2G6基因发生复合杂合变异，分别来自父亲携带的杂合子变异c.496dupG (p.Glu166fsTer32)及其母亲携带的杂合子变异c.2189T>G (p.Met730Arg)。变异p.Met730Arg尚未被报道，蛋白结构预测该变异蛋白结构稳定性可能发生改变，体外检测结果表明该变异蛋白表达量显著降低。本研究进一步丰富了PLA2G6基因变异谱，有助于提升临床医生对INAD疾病的诊断意识。.