Table 1.

Causes of primary [congenital] microcephaly: overview.

1.Genetic causes Numerical chromosomal aberrations or microdeletion and/or duplication syndromes Trisomy 13, 18, 21, etc. Monogenetic microcephaly Autosomal recessive microcephaly (MCPH1-10, MCPHA) Nijmegen breakage syndrome (MIM#251260) Autosomal dominant microcephaly X-chromosomal microcephaly Aicardi–Goutieres syndrome (MIM#225750, 610329, 610181, 610333, 612952) Cockayne syndrome (MIM#216400, 133540, 216411) Cornelia de Lange syndrome (MIM#122470, 610759, 614701, 300590, 300822) Rubinstein–Taybi syndrome (MIM#180849) Feingold syndrome (MIM#164280, 614326) Rett syndrome, congenital (MIM#164874) Mowat–Wilson syndrome (MIM#235730) Smith–Lemli–Opitz syndrome (MIM#270400) Seckel syndrome (MIM#210600, 606744, 608664, 613676, 613823, 61472) Ligase IV syndrome (MIM #606593) Mutations in ATRX gene (MIM*300032) Mutations in ARX gene (MIM*300382) Mutations in PQBP1 gene (MIM*300463) Mutations in ASNS gene (MIM*108370) Borjeson–Forssman–Lehmann syndrome (MIM#301900) Imprinting disorders Angelman syndrome (MIM#105830) 2.Metabolic cause (genetic aetiology) Serine biosynthesis disorder Sterol biosynthesis disorder Mitochondriopathy, e.g. pyruvate dehydrogenase deficiency Congenital disorders of glycosylation syndrome Rare congenital metabolic diseases (see text) 3.Exogenic factors Intrauterine infection Toxoplasmosis, rubella, cytomegalovirus, herpes simplex, varicella zoster virus, syphilis, human immunodeficiency virus, Zika Virusa, Lymphocytic Choriomeningitis Virus (LCMV)a Teratogens Alcohol, cocaine, antiepileptic drugs, lead/mercury intoxication, radiation Disruptive incident Vascular incident (stroke), intrauterine death of twin Maternal disease Hyperphenylalaninaemia Maternal anorexia nervosa Extreme insufficiency of placenta 4.Craniosynostosis

Reproduced with permission from Von der Hagen et al. [22].

^aNot included in original table from Von der Hagen et al.