Elsevier

Pediatric Neurology

Volume 37, Issue 2, August 2007, Pages 148-151
Pediatric Neurology

Case report
Megalencephaly and Polymicrogyria with Polydactyly Syndrome

https://doi.org/10.1016/j.pediatrneurol.2007.04.008Get rights and content

We report the clinical manifestations of a 26-month-old Japanese girl with megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome. She was born to healthy, nonconsanguineous parents at 37 weeks by caesarian section after prenatal ultrasonography suggested hydrocephalus. Macrocephaly and polydactyly of both lower extremities were noted at birth. At 3 months of age, epileptic seizures developed. The patient displayed impaired vision and profound global developmental delay. Magnetic resonance imaging of the brain revealed dilatation of the lateral and third ventricles with cavum septi pellucidi et vergae and generalized polymicrogyria, most prominent in both perisylvian regions and the right frontal region. Despite ventriculomegaly, radionuclide cisternography indicated normal cerebrospinal circulation, suggesting that pathogenesis of the megalencephaly was unrelated to obstructive hydrocephalus. Decreased white matter volume and abnormal signal intensity in the occipital lobes were also noted. Visual disturbance due to white matter abnormality appears to represent a significant characteristic of this syndrome. The genetic background of the syndrome remains unclear.

Introduction

Polymicrogyria is a malformation of cortical development characterized by multiple small gyri with derangement of the normal cortical lamination [1]. Several specific bilateral polymicrogyria syndromes have been recognized [2], [3], [4], [5], [6], [7], and polymicrogyria has also been described in several multiple congenital anomaly syndromes and chromosome aneuploidy syndromes [7], [8]. Recently, Mirzaa et al. [9] described five unrelated patients who presented with perisylvian polymicrogyria, megalencephaly, mental retardation, seizures, polydactyly and hydrocephalus and designated this the megalencephaly-polymicrogyria-polydactyly-hydrocephalus (MPPH) syndrome. Colombani et al. [10] reported another case, giving a total of just 6 reported cases prior to the present report. The etiology of MPPH syndrome remains unknown, and the genetic background of this syndrome is also unclear.

The present report describes the case of a Japanese patient with MPPH syndrome who exhibited severely impaired vision and asymmetric involvement on magnetic resonance imaging of the brain. The clinical manifestations noted in this patient and in previously described cases suggest that MPPH syndrome displays phenotypic and neuroradiological variations.

Section snippets

Case Report

A 26-month-old girl was the first daughter born to healthy, nonconsanguineous Japanese parents with unremarkable family history. At 30 weeks of gestation, ventricular dilatation of the brain was suspected from intrauterine ultrasonography. The child was delivered at 37 weeks of gestation by caesarean section. At birth, body weight was 3258 g, body length was 49 cm, and head circumference was 37.6 cm (+3.5 standard deviations). Macrocephalus and polydactyly of both lower extremities were evident

Discussion

The present report brings to six the number of cases of MPPH syndrome in the literature, after the original five cases described by Mirzaa et al. [9] and the additional case reported by Colombani et al. [10]. An association of macrocephaly and polymicrogyria has been described in several multiple congenital malformations, and three sporadic cases of megalencephaly-polymicrogyria-mega corpus callosum syndrome have been reported [11]. Mirzaa et al. [9] speculated that this malformation syndrome

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