Pontine Tegmental Cap Dysplasia in an Extremely Low Birth Weight Preterm Infant

Case Study: Pontine tegmental cap dysplasia (PTCD) is a rare hindbrain and cranial nerve malformation syndrome characterized by distinct imaging findings. The latter includes pontine hypoplasia with ventral flattening and a dorsal “tegmental cap,” that is, a thorn-like tissue protrusion into the fourth ventricle. So far, only 27 sporadic cases have been described. Here, we provide an overview of the phenotype and report the first extremely low birth weight preterm infant with PTCD as the severe end of the disease spectrum. We highlight an agonizingly painful blepharospasm suggestive of trigeminal and possibly facial nerve impairment as a new feature in PTCD and illustrate prenatal cranial imaging findings suggestive of the disease. As the underlying genetic cause of PTCD remains unknown, we performed chromosome analysis, array CGH and whole-exome sequencing. We present the corresponding results and discuss potential candidate genes/regions. Our report can likely promote the diagnosis of PTCD in further patients and support the identification of the underlying genetic cause.

Keywords: pontine tegmental cap dysplasia, PTCD, pontine hypoplasia, sensorineural deafness, preterm infant.