An unusual association of microcephalic osteodysplastic primordial dwarfism type I with cardiac and brain anomalies.

Less than 100 cases of primordial dwarfism have been reported worldwide out of which Microcephalic osteodysplastic primordial dwarfism type I comprise about <30 cases. We report a rare case of extreme growth failure in a neonate with primordial dwarfism of antenatal onset due to Microcephalic osteodysplastic primordial dwarfism type I. Our case is also unique in being associated with hitertho unreported association of subpulmonic ventricular septal defect and a dorsal interhemispheric cyst in the brain.

INTRODUCTION

Primordial dwarfism is a specific type of severe proportionate dwarfism, in which individuals are small for their chronological age from the very beginning of life. Microcephalic osteodysplastic primordial dwarfism type I (MOPD I) is the rarest type. To the best of our knowledge this is the first case of MOPD I from India. Reported here is also an extremely rare association of MOPD I with cardiovascular and brain malformations.

We report a case of 800 g male baby born out of a non-consanguineous marriage, at 38 weeks, who presented with severe intra uterine growth restriction (IUGR), length (35 cm) and head circumference (25 cm) both below 3rd centile, peculiar facies [Figure 1] alopecia totalis, prominent eyes, megalocornea, low set dysplastic ears [Figure 2], short neck, broad nasal tip, flat malar region, micrognathia, cryptorchidism, micropenis and a rocker bottom foot. The clinical diagnosis was consistent with classical MOPD I. Echocardiography revealed a 0.8 mm subpulmonic ventricular septal defect (VSD). Antenatal ultrasound had revealed severe oligohydramnios and hypoplastic cerebrum with porencephalic cyst. Postnatal magnetic resonance imaging (MRI) brain showed pachygyria with multiple areas of gyral widening, corpus callosum agenesis with a left paramedian dorsal inter-hemispheric cyst. Infantogram revealed mild bowing of the femoral diaphysis and absent epiphysis of the distal end of the femur. Investigations for intrauterine infections, metabolic, endocrine and chromosomal disorders were negative. Baby had uneventful neonatal period and was discharged on breast feeds. However, he succumbed to septicemia at 3 months of age.

Figure 1

Alopecia totalis, prominent eyes, pointed nose, micrognathia

Figure 2

Alopecia totalis, dysplastic low set ears

Primordial dwarfism is a disorder of extreme growth failure of prenatal onset. It encompasses distinct entities including Russell-Silver syndrome, Seckel syndrome, Meier-Gorlin syndrome and MOPD types I/III and II.

MOPD I is synonymous with Brachymelic primordial dwarfism, Taybi Linder syndrome, Cephalo-skeletal dysplasia, low birth weight dwarfism with skeletal dysplasia.[1]

MOPD I phenotype consists of severe IUGR, microcephaly, neuronal migration abnormalities, absent/sparse hair including scalp hair, eyebrows and eyelashes, dry and aged-appearing skin, multiple joint contractures and skeletal anomalies such as reduced height of the vertebrae, long clavicles, bowed femora or hip dislocation. Many children have abnormalities in the brain seen on MRI, such as corpus callosum agenesis, abnormal gyration, pachygyria. Diagnosis is clinical although genetic analysis is possible. Average life expectancy is about 8.5 months (range 2.5-18 months). Death usually occurs before 1 year of age due to intercurrent infections.[23] Surviving infants suffer from recurrent apneas, seizures and psychomotor retardation.

Our case had classical features of MOPD I described above and in addition had unusual association with a dorsal inter-hemispheric cyst in the brain and VSD.