Congenital Genetic Microcephaly: Clinical Diagnostic Approach

Microcephaly is an important neurological sign defined by a cranial circumference < 2 standard deviations or < 3 standard deviations in the severe form compared with age- and gender-matched children. Microcephaly is classified as congenital (prenatal) and postnatal. In general, microcephaly may result from an insult, including infections, metabolic diseases, cerebral malformations, and/or genetic syndromes that disturb early brain growth. Clinical history, the trajectory of the child's growth in terms of head circumference, and a detailed physical examination will often be suggestive of a diagnostic workup. Advances in neuroimaging and especially genetics have yielded improvements in understanding the causes of microcephaly, leading to new approaches in diagnosis, treatment, and prevention. The aim of the present study is to report the current practice for the diagnostic algorithm of genetic microcephaly, with prenatal onset.