is a neurological condition in which a person's head is significantly smaller than normal for their age and sex, based on standardized charts. This condition, which most often occurs because the brain fails to grow at a normal rate, can be present at birth or it may develop in the first few years of life. Conditions that affect brain growth and can cause microcephaly include infections, genetic disorders, severe malnutrition and other environmental factors. Some children with microcephaly will be of normal intelligence and development. However, many children with microcephaly experience complications such as developmental delays, difficulties with balance and coordination, short stature, hyperactivity, mental retardation, seizures or other neurological abnormalities. While there's no treatment for microcephaly, early intervention may help enhance development and improve quality of life. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.