Microcephaly is a neurological condition in which the skull and brain develop significantly smaller than expected for age and sex. Because skull growth is driven by brain growth, microcephaly leaves a distinct and recognizable imprint on the cranium, often including a reduced cranial vault, sloping forehead, and altered proportions between the face and skull cap. Microcephaly can be congenital or acquired, with causes ranging from genetic conditions and chromosomal abnormalities to prenatal infe