microcephaly with or without short stature
Primary microcephaly refers to the clinical finding of a head circumference more than than 3 standard deviations (SD) below the age- and sex-related mean, present at birth. Primary microcephaly is a static developmental anomaly, distinguished from secondary microcephaly, which refers to a progressive neurodegenerative condition. Microcephaly is a disorder of fetal brain growth; individuals with microcephaly have small brains and almost always have intellectual disability, although rare individuals with mild microcephaly (-3 SD) and normal intelligence have been reported. Additional clinical features may include short stature or mild seizures. These clinical features include Seckel syndrome, a rare autosomal recessive disorder characterized by intrauterine growth retardation, dwarfism, microcephaly with intellectual disability.