Background Pelizaeus-Merzbacher disease （PMD） is a rare X-linked recessive disorder with symptoms including nystagmus, impaired motor development, ataxia, and progressive spasticity. The proteolipidprotein 1 （PLP1...Background Pelizaeus-Merzbacher disease （PMD） is a rare X-linked recessive disorder with symptoms including nystagmus, impaired motor development, ataxia, and progressive spasticity. The proteolipidprotein 1 （PLP1） gene is the only pathogenic gene of PMD. Duplication of the PLP1 gene is the most frequent gene defect, accounting for 50%-70% of PMD cases, whereas point mutations in the coding sequence or the splice sites account for 10%-25% of PMD cases. This study aimed to identify PLP1 mutations in nine unrelated Chinese patients （P1-9） with PMD, and 14 subjects from the family of patient 2 were also described. Methods Genomic DNA was extracted from peripheral multiplex ligation-dependent probe amplification （MLPA）. AI amplified and analyzed using direct DNA sequencing. blood samples. Gene dosage was determined using the 7 exons and exon-intron boundaries of the PLP1 gene were Results Of these nine patients, there were four transitional, four classical, and one connatal PMD according to their clinical and radiological presentations. PLP1 duplications were identified in patients 1-7 with PMD. Their mothers were PLPI duplications carriers as well. Both duplication carriers and normal genotypes of PLP1 were identified in the family members of patient 2. A c.517C〉T （p. P173S） hemizygous missense mutation in exon 4 was found in patient 8 with PMD, and his mother was shown to be a heterozygote of this mutation. Conclusions We identified seven genomic duplications and one missense mutation （p. P173S） of the PLP1 gene in eight Chinese patients with PMD. This is the report about PLP1 mutations in PMD patients from the mainland of China.展开更多
Alzheimer＇s disease（AD） is a neurodegenerative disorder in which amyloid b plaques are a pathological characteristic. Little is known about the physiological functions of amyloid b precursor protein（APP）. Based o...Alzheimer＇s disease（AD） is a neurodegenerative disorder in which amyloid b plaques are a pathological characteristic. Little is known about the physiological functions of amyloid b precursor protein（APP）. Based on its structure as a type I transmembrane protein, it has been proposed that APP might be a receptor, but so far, no ligand has been reported. In the present study, 9 proteins binding to the extracellular domain of APP were identified using a yeast two-hybrid system. After confirming the interactions in the mammalian system, mutated PLP1,members of the FLRT protein family, and KCTD16 were shown to interact with APP. These proteins have been reported to be involved in Pelizaeus-Merzbacher disease（PMD） and axon guidance. Therefore, our results shed light on the mechanisms of physiological function of APP in AD, PMD, and axon guidance.展开更多
文摘Background Pelizaeus-Merzbacher disease （PMD） is a rare X-linked recessive disorder with symptoms including nystagmus, impaired motor development, ataxia, and progressive spasticity. The proteolipidprotein 1 （PLP1） gene is the only pathogenic gene of PMD. Duplication of the PLP1 gene is the most frequent gene defect, accounting for 50%-70% of PMD cases, whereas point mutations in the coding sequence or the splice sites account for 10%-25% of PMD cases. This study aimed to identify PLP1 mutations in nine unrelated Chinese patients （P1-9） with PMD, and 14 subjects from the family of patient 2 were also described. Methods Genomic DNA was extracted from peripheral multiplex ligation-dependent probe amplification （MLPA）. AI amplified and analyzed using direct DNA sequencing. blood samples. Gene dosage was determined using the 7 exons and exon-intron boundaries of the PLP1 gene were Results Of these nine patients, there were four transitional, four classical, and one connatal PMD according to their clinical and radiological presentations. PLP1 duplications were identified in patients 1-7 with PMD. Their mothers were PLPI duplications carriers as well. Both duplication carriers and normal genotypes of PLP1 were identified in the family members of patient 2. A c.517C〉T （p. P173S） hemizygous missense mutation in exon 4 was found in patient 8 with PMD, and his mother was shown to be a heterozygote of this mutation. Conclusions We identified seven genomic duplications and one missense mutation （p. P173S） of the PLP1 gene in eight Chinese patients with PMD. This is the report about PLP1 mutations in PMD patients from the mainland of China.
基金supported by the National Natural Science Foundation of China for Distinguished Young Scholars(81425009)the Beijing Natural Science Foundation,China(7142085)the Peking University Collaborative Fund,China(464-10606-00416)
文摘Alzheimer＇s disease（AD） is a neurodegenerative disorder in which amyloid b plaques are a pathological characteristic. Little is known about the physiological functions of amyloid b precursor protein（APP）. Based on its structure as a type I transmembrane protein, it has been proposed that APP might be a receptor, but so far, no ligand has been reported. In the present study, 9 proteins binding to the extracellular domain of APP were identified using a yeast two-hybrid system. After confirming the interactions in the mammalian system, mutated PLP1,members of the FLRT protein family, and KCTD16 were shown to interact with APP. These proteins have been reported to be involved in Pelizaeus-Merzbacher disease（PMD） and axon guidance. Therefore, our results shed light on the mechanisms of physiological function of APP in AD, PMD, and axon guidance.
