Microcephaly (cont.)

It is most often caused by genetic abnormalities that interfere with the growth of the cerebral cortex during the early months of fetal development. It is associated with Down's syndrome, chromosomal syndromes, and neurometabolic syndromes. Babies may also be born with microcephaly if, during pregnancy, their mother:

• abused drugs or alcohol,
• became infected with a cytomegalovirus,
• rubella (German measles), or varicella (chickenpox) virus,
• was exposed to certain toxic chemicals, or
• had untreated phenylketonuria (PKU).

Babies born with microcephaly will have a smaller than normal head that will fail to grow as they progress through infancy.

Depending on the severity of the accompanying syndrome, children with microcephaly may have:

• mental retardation,
• delayed motor functions and speech,
• facial distortions,
• dwarfism or short stature,
• hyperactivity,
• seizures,
• difficulties with coordination and balance, and
• other brain or neurological abnormalities.

Some children with microcephaly will have normal intelligence and a head that will grow bigger, but they will track below the normal growth curves for head circumference.

Source: MedicineNet.com
http://www.medicinenet.com/microcephaly/article.htm