Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder, characterized by an early symptomatic onset with rapid progression of psycho- motor regression and hypotonia, evolving into spasticity. This results in total neurological degeneration and mortality by th

Infantile neuroaxonal dystrophy (INAD) is a rare neurodegenerative disease with early onset. PLA2G6 gene mutations have been identified in the majority individuals with INAD. In future, molecular diagnosis of INAD will replace the invasive biopsies used previously. In the present report, monozygotic male twins with INAD were referred The Children's Hospital (Zhejiang University School of Medicine, Zhejiang, China) at fifteen months old for delayed development. The older brother was found to have developmental stagnation when he was 6 months old. The patient could not stand securely without support, and had poor eye tracking and listening ability. Magnetic resonance imaging (MRI) of the patient's brain revealed cerebellar atrophy and electromyography identified signs of peripheral neuropathy. The younger brother displayed similar clinical features and findings. Two different phospholipase A2 group VI (PLA2G6; 22q13.1) gene mutations were detected in the twins by DNA sequencing. The results of the present study indicate that neurogenetic disease should be considered when child patients present with idiopathic developmental stagnation, particularly when similar cases have appeared in the same family. In addition, INAD should be considered as a possible diagnosis when the patient has developmental delay of the central and peripheral nerves. In the future, molecular genetic testing will be the primary method of INAD diagnosis, enabling better prevention of this genetic disease. Introduction Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder, characterized by an early symptomatic onset with rapid progression of psychomotor regression and hypotonia, evolving into spasticity. This results in total neurological degeneration and mortality by the age of 10. There is no effective treatment for INAD at present and since it is a rare disorder, involving axons in the central and peripheral nervous system, there is little literature on the disease. Therefore, it is important to provide accurate genetic counseling for families with INAD. INAD sufferers exhibit spheroid bodies in the central nervous system and pathological swelling of axons (1). In addition, T2-weighted magnetic resonance imaging (MRI) of patients with INAD typically reveals cerebellar atrophy, however, MRI is not used as the primary method of INAD diagnosis (2,3). Prior to molecular testing for phospholipase A2 group VI (PLA2G6; 22q13.1) mutations, which have been identified in the majority of INAD sufferers, an INAD diagnosis could be only be confirmed through electron microscopy identification of axon dystrophy in a tissue biopsy of conjunctiva, skin, muscle or sural nerves (4). Molecular diagnosis of INAD eliminates the need for invasive biopsies, enables the detection of carriers of INAD-associated mutations and allows for prenatal diagnosis. The present study reports the case twins with INAD caused by PLA2G6 mutations inherited from the mother and father, which highlights the importance of genetic testing in the diagnosis and prevention of INAD.