BACKGROUND: Two unrelated girls had early onset of nystagmus and epilepsy, absent psychomotor development, and almost complete absence of myelin on cerebral MRI. The clinical features and MR images of both patients resembled the connatal form of Pelizaeus-Merzbacher disease (PMD), which is an X-linked recessive disorder caused by duplications or mutations of the proteolipid protein gene (PLP). OBJECTIVE: To define a unique neurometabolic disorder with failure of myelination. METHOD: S AND RESULTS: 1H-NMR of CSF in both girls was performed repeatedly, and both showed highly elevated concentrations of N-acetylaspartylglutamate (NAAG). The coding sequence of the gene coding for glutamate carboxypeptidase II, which converts NAAG to N-acetylaspartate (NAA) and glutamate, was entirely sequenced but revealed no mutations. Even though both patients are girls, the authors sequenced the PLP gene and found no abnormality. CONCLUSIONS: NAAG is an abundant peptide neurotransmitter whose exact role is unclear. NAAG is implicated in two cases of unresolved severe CNS disorder. Its elevated concentration in CSF may be the biochemical hallmark for a novel neurometabolic disorder. The cause of its accumulation is still unclear.
BACKGROUND: Two unrelated girls had early onset of nystagmus and epilepsy, absent psychomotor development, and almost complete absence of myelin on cerebral MRI. The clinical features and MR images of both patients resembled the connatal form of Pelizaeus-Merzbacher disease (PMD), which is an X-linked recessive disorder caused by duplications or mutations of the proteolipid protein gene (PLP). OBJECTIVE: To define a unique neurometabolic disorder with failure of myelination. METHOD: S AND RESULTS:1H-NMR of CSF in both girls was performed repeatedly, and both showed highly elevated concentrations of N-acetylaspartylglutamate (NAAG). The coding sequence of the gene coding for glutamate carboxypeptidase II, which converts NAAG to N-acetylaspartate (NAA) and glutamate, was entirely sequenced but revealed no mutations. Even though both patients are girls, the authors sequenced the PLP gene and found no abnormality. CONCLUSIONS:NAAG is an abundant peptide neurotransmitter whose exact role is unclear. NAAG is implicated in two cases of unresolved severe CNS disorder. Its elevated concentration in CSF may be the biochemical hallmark for a novel neurometabolic disorder. The cause of its accumulation is still unclear.
Authors: John R Moffett; Brian Ross; Peethambaran Arun; Chikkathur N Madhavarao; Aryan M A Namboodiri Journal: Prog Neurobiol Date: 2007-01-05 Impact factor: 11.685
Authors: Nicole I Wolf; Maria Cundall; Paul Rutland; Elisabeth Rosser; Robert Surtees; Sarah Benton; Wui K Chong; Sue Malcolm; Friedrich Ebinger; Maria Bitner-Glindzicz; Karen J Woodward Journal: Neurogenetics Date: 2006-09-13 Impact factor: 2.660
Authors: F Mochel; U F H Engelke; J Barritault; B Yang; N H McNeill; J N Thompson; A Vanderver; N I Wolf; M A Willemsen; F W Verheijen; F Seguin; R A Wevers; R Schiffmann Journal: Neurology Date: 2010-01-26 Impact factor: 9.910
Authors: Eduardo F Sanches; Yohan Van de Looij; Audrey Toulotte; Analina R da Silva; Jacqueline Romero; Stephane V Sizonenko Journal: Front Neurol Date: 2018-06-25 Impact factor: 4.003