Pitt-Hopkins syndrome in two patients and further definition of the phenotype.

Pitt-Hopkins syndrome is a rare dysmorphic mental retardation syndrome marked by daytime spells of overbreathing interrupted by apnoea. The dysmorphism consists of a large beaked nose, cup-shaped ears with broad helices, a wide mouth, Cupid's bow upper lip, wide and shallow palate and broad or clubbed fingertips. The four patients described so far have been sporadic and represented both sexes. In addition, a pair of sibs with atypical features has been reported as possible Pitt-Hopkins syndrome cases. We describe two unrelated Pitt-Hopkins syndrome patients in order to further define the phenotype. In addition to severe developmental retardation, hypotonia, postnatal growth retardation, microcephaly, abnormal breathing and characteristic dysmorphic features, both had epilepsy and intestinal problems with severe constipation in one and Hirschsprung disease in the other. Other abnormalities were hypopigmented skin macules in one and high-grade myopia in the other. Both had unusual frontal slow-and-sharp-wave discharges on electroencephalography. Magnetic resonance imaging in both showed a similar hypoplastic corpus callosum with missing rostrum and posterior part of the splenium and bulbous caudate nuclei bulging towards the frontal horns. Chromosomal analysis and subtelomere fluorescence in-situ hybridization studies were normal. No mutations were found in the MECP2 or ZFHX1B genes. Extensive metabolic and mitochondrial screens were normal. The electroencephalography and brain magnetic resonance imaging findings appear to be further diagnostic signs in Pitt-Hopkins syndrome, which is also one of the syndromes associated with Hirschsprung disease.

Hypertrichosis, hyperkeratosis, abnormal corpus callosum, mental retardation and dysmorphic features in three unrelated females.

We report three unrelated patients with hypertrichosis, mild to moderate mental retardation, and dysmorphic facial features including low anterior hairline, thick arched eyebrows, nose with broad tip and columella below alae nasi, short philtrum, thick drooping lower lip and simple posteriorly rotated ears. They also had rough skin with hyperkeratotic plaques. Feet and finger tips were broad. All of them had personality problems like aggressiveness, stubborn temperament or tendency to withdraw. Brain MRI showed thick and short corpus callosum. We believe that these patients represent a new syndrome of unknown aetiology.

Temporo-occipital spikes: a typical EEG finding in Kabuki syndrome.

Kabuki syndrome is a rare dysmorphogenic disorder. The central nervous system is often involved, and epilepsy is a common symptom. The diagnosis is clinical, and no typical electroencephalographic findings have thus far been reported. We have documented temporo-occipital spikes in sleep electroencephalogram in all our three Kabuki patients. The location of the spikes was similar in all cases although their occurrence varied from continuous spiking to single spikes. We suggest that temporo-occipital spikes are typical in Kabuki syndrome and discuss the possible cause of this finding.

18q-syndrome: brain MRI shows poor differentiation of gray and white matter on T2-weighted images.

PURPOSE: To study brain MRI findings in patients with 18q- syndrome and to correlate these findings with the results of the molecular breakpoint analysis. MATERIALS AND METHODS: Brain MR images of 17 patients with 18q- syndrome were evaluated. Segregation analysis was performed with 15 microsatellite markers to determine the deletion breakpoints and whether the deletion included the myelin basic protein (MBP) gene. RESULTS: One patient had an interstitial deletion of 18q which spared the MBP gene. He was the only one with normal brain MRI. All 16 patients with deletions including the MBP gene had abnormal white matter in MRI. The main finding was poor differentiation of gray and white matter on T2-weighted images due to increased white matter signal intensity. In addition, measured signal intensity of the white matter was significantly increased in patients compared with controls. CONCLUSIONS: Poor differentiation of gray and white matter on T2-weighted images is the most typical MRI finding of the 18q- syndrome. These results support the postulation that abnormal myelination in 18q- syndrome is due to haploinsufficiency at or near the MBP locus.