Pontine Tegmental Cap Dysplasia With a 2q13 Microdeletion Involving the NPHP1 Gene: Insights Into Malformations of the Mid-Hindbrain

The case of a young man with multiple brain and somatic anomalies that presented diagnostic difficulties, is discussed in this report. A majority of his features were suggestive of Joubert syndrome—although it was felt that he did not fully meet diagnostic criteria. The subsequent evaluations included a magnetic resonance image of the brain, that was found to be consistent with pontine tegmental cap dysplasia. Chromosomal microarray studies showed a 2q13 deletion. A gene associated with Joubert syndrome, NPHP1, is within this region. This case highlights several important aspects of the diagnosis and nosology of malformations of the mid-hind brain.