_:vb50939547 . _:vb50939547 . _:vb50939547 "url:https://www.ncbi.nlm.nih.gov/pubmed/18818955"^^ . _:vb50939547 "A metal metabolism disorder characterized by very low serum magnesium levels often with secondary hypocalcemia with onset typically in the first months of life."^^ . _:vb50939547 . _:vb50939547 . _:vb50939547 .