Primary microcephaly in Hungary: epidemiology and clinical features

Abstract Aim: To describe the population‐based epidemiological characteristics and clinical features of primary microcephaly in Hungary. Methods: A retrospective survey of patients born with microcephaly in a region (Dél‐Alföld – South Great Plain) in Hungary between July 1, 1992 and June 30, 2006 was performed. Patients with microcephaly and without any environmental or obstetric risk factors and/or dysmorphism (primary microcephaly) were included in the study. The birth prevalence of primary microcephaly per 10 000 live births was calculated. Results: Ten patients (8 girls and 2 boys) were found with primary microcephaly among 185 486 live births, which corresponds to a birth prevalence of 0.54 per 10 000 live births (95% confidence interval: 0.20–0.87). Developmental delay and intellectual disability were the main clinical features. Dyskinesia was seen in one and epilepsy was diagnosed in two patients. The MRI revealed simplified gyral pattern in all patients. Conclusion: Primary microcephaly is a very rare brain malformation, although the birth prevalence found in this survey is slightly higher than the few figures published earlier. As more and more genes and mutations responsible for primary microcephaly are discovered, the ascertainment of these rare cases is mandatory to provide the parents with genetic counselling.