{Reference Type}: Case Reports {Title}: Thin genu of the corpus callosum points to mutation in FOXG1 in a child with acquired microcephaly, trigonocephaly, and intellectual developmental disorder: a case report and review of literature. {Author}: De Bruyn C;Vanderhasselt T;Tanyalçin I;Keymolen K;Van Rompaey KL;De Meirleir L;Jansen AC; {Journal}: Eur J Paediatr Neurol {Volume}: 18 {Issue}: 3 {Year}: May 2014 {Factor}: 3.692 {DOI}: 10.1016/j.ejpn.2013.11.010 {Abstract}: The FOXG1 syndrome is emerging as a relative new entity in paediatric neurology. We report a boy with acquired microcephaly, mental retardation and a thin genu of the corpus callosum. The combination of these findings led to mutation analysis of FOXG1. The patient was found to be heterozygous for a novel mutation in FOXG1, c.506dup (p.Lys170GInfsX285), which occurred de novo. This frameshift mutation disturbs the three functional domains of the FOXG1 gene. Hypo- or agenesis of the anterior corpus callosum in combination with acquired microcephaly and neurologic impairment can be an important clue for identifying patients with a mutation in FOXG1.