Arts syndrome with a novel missense mutation in the PRPS1 gene: A case report
BRAIN & DEVELOPMENT
Authors: Maruyama, Koichi; Ogaya, Shunsuke; Kurahashi, Naoko; Umemura, Ayako; Yamada, Keitaro; Hashiguchi, Akihiro; Takashima, Hiroshi; Torres, Rosa J.; Aso, Kosaburo
Abstract
Arts syndrome is characterized by early-onset hypotonia, ataxia, intellectual disability, sensorineural hearing impairment, progressive optic atrophy, and a tendency to develop infections. Arts syndrome is an X-linked disorder caused by a loss-of-function mutation in the PRPS1 gene, which encodes phosphoribosylpyrophosphate synthetase 1. Only three families have been reported. Here, we report another family with Arts syndrome. The initial symptoms of the 1-year-old proband were hypotonia and ataxia, worsening recurrent infection-triggered muscle weakness, motor and intellectual developmental delay, and hearing loss. Both central nervous system involvement and peripheral neuropathy were demonstrated. His three maternal uncles had died before the age of 3 years. A genetic analysis of PRPS1 revealed a novel missense mutation, c.367C>G (p.His123Asp). PRPS enzymatic activity was markedly reduced in the patient. His mothek was supposed to be an asymptomatic carrier. Arts syndrome should be included in the differential diagnosis of infantile hypotonia and weakness aggravated by recurrent infection with a family history of X-linked inheritance. (C) 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
The function of the three phosphoribosyl pyrophosphate synthetase (Prs) genes in hyphal growth and conidiation in Aspergillus nidulans
MICROBIOLOGY-SGM
Authors: Jiang, Ping; Wei, Wen-fan; Zhong, Guo-wei; Zhou, Xiao-gang; Qiao, Wei-ran; Fisher, Reinhard; Lu, Ling
Abstract
Phosphoribosyl pyrophosphate synthetase, which is encoded by the Prs gene, catalyses the reaction of ribose-5-phosphate and adenine ribonucleotide triphosphate (ATP) and has central importance in cellular metabolism. However, knowledge about how Prs family members function and contribute to total 5-phosphoribosyl-alpha-1-pyrophosphate (PRPP) synthetase activity is limited. In this study, we identified that the filamentous fungus Aspergillus nidulans genome contains three PRPP synthase-homologous genes (AnprsA, AnprsB and AnprsC), among which AnprsB and AnprsC but not AnprsA are auxotrophic genes. Transcriptional expression profiles revealed that the mRNA levels of AnprsA, AnprsB and AnprsC are dynamic during germination, hyphal growth and sporulation and that they all showed abundant expression during the vigorous hyphal growth time point. Inhibiting the expression of AnprsB or AnprsC in conditional strains produced more effects on the total PRPP synthetase activity than did inhibiting AnprsA, thus indicating that different AnPrs proteins are unequal in their contributions to Prs enzyme activity. In addition, the constitutive overexpression of AnprsA or AnprsC could significantly rescue the defective phenotype of the AnprsB-absent strain, suggesting that the function of AnprsB is not a specific consequence of this auxotrophic gene but instead comes from the contribution of Prs proteins to PRPP synthetase activity.