FoxG1 Syndrome is characterized by microcephaly and brain malformations. Infection during pregnancy causes microcephaly and other brain malformations in some babies. This can result in microcephaly, severe brain malformations, and other birth defects. Microphthalmia and microcephaly are frequent congenital defects in FA patients. A mutation in these gene is responsible for autosomal recessive primary microcephaly. Congenital brain abnormalities other than microcephaly have also been reported after a Zika outbreak. The microcephaly and gyrification malformations are permanent and there are no known treatments. Genetic mutations cause most cases of microcephaly. Achalasia can also manifest alongside other diseases as a rare syndrome such as achalasia microcephaly. Mutations that result solely in microcephaly (primary microcephaly) exist but are less common. In case of fetuses with microcephaly, 58% of the population expressed opposition. Infants with microcephaly are born with either a normal or reduced head size. MCPH1 codes for microcephalin, and disorders in this and in ASPM are associated with microcephaly. However, the older, slightly more traditional classification, "microcephaly", translates to, "smallness of brain". There were concerns that Zika virus caused microcephaly.