Preferred term: Microcephaly
Alt. terms: Small head | Decreased size of skull | Abnormally small cranium

HPO term: Microcephaly
HPO code: HP:0000252

GenIA ID: 261
Last updated on: 2024-10-23 14:29:58

Cross ref. with other ontologies

NCIT: C85874
MESH: D008831
EFO: -
OAE: -
SNOMEDCT: -
ICD10: Q02

Head circumference below 2 standard deviations below the mean for age and gender. Head circumference is measured from just above the glabella (the most prominent point on the frontal bone above the root of the nose) to the most posterior prominent point of the occipital bone using a tape measure. Some standard charts are organized by centiles Hall et al. 2007, others by standard deviations Farkas, 1981. It is important to add an indication of how far below the normal standard the head circumference is if an accurate assessment of this can be made. Microcephaly is an absolute term. The term relative microcephaly can be used when the head size centile is less than the centile for height, for example, head size at the 3rd centile with height at the 75% for age and sex. On prenatal ultrasound, microcephaly is diagnosed if the head circumference or the biparietal diameter is more than three standard deviations below the mean.

PARENT terms

• Aplasia/Hypoplasia of the cerebrum
• Decreased head circumference

TERM

Microcephaly

CHILD terms

• Secondary microcephaly
• Primary microcephaly