Jubinsky et al. (2006) reported 3 sibs, born of nonconsanguineous Mexican parents, with holoprosencephaly (HPE), recurrent infections, and increased peripheral blood monocytes. All had microcephaly, dysmorphic facies, severe developmental delay, failure to thrive, and brachydactyly. The clinical courses ... Jubinsky et al. (2006) reported 3 sibs, born of nonconsanguineous Mexican parents, with holoprosencephaly (HPE), recurrent infections, and increased peripheral blood monocytes. All had microcephaly, dysmorphic facies, severe developmental delay, failure to thrive, and brachydactyly. The clinical courses were complicated by multiple recurrent respiratory and skin infections associated with peripheral blood monocytosis with abnormal morphology. Brain imaging and postmortem examination showed agenesis of the corpus callosum, interhemispheric cyst, lobar HPE, and other brain anomalies. The patients died of sepsis at ages 6 years, 8 months, and 4.5 years, respectively. Mutation analyses of genes known to be involved in HPE (see 236100) were negative. Since a previous infant born of a different father was also reportedly affected, the authors suggested a maternally transmitted autosomal dominant trait that may involve a defect in the monocyte/glial cell population.