A serine deficiency that is characterized by multiple fatal malformations including ichthyosis, microcephaly, central nervous system abnormalities, limb deformities, intrauterine growth restriction, proptosis, anasarca, and micrognathia, and has_material_basis_in autosomal recessive inheritance of mutation in the PHGDH gene on chromosome 1p12, causing issues producing the amino acid serine.