To determine whether MKL2 or SRF variants occurred in other unrelated cases of microcephaly of varying severity, we first sequenced MKL2 exon 10 (N = 11) and SRF untranslated region (UTR) and coding regions (N = 15 including 11 sequenced at MKL2 and four additional cases) from DNA isolated from FFPE sections of fetal (>20 weeks gestation) and neonatal brain tissue collected at Washington University (Table S2). The gene discussed is MRTFB; the disease is microcephaly.