Niemann Pick Disease as a Cause of Recurrent Non-immune Hydrops .Fetalis Causing Neonatal Death

Abstract

Introduction Fetal hydrops is defined as the accumulation of fluid in the interstitial tissues (skin) and two serous cavitiesl'2. It is further subdivided into 'imrnune' or 'non-immune', a distinction made on the presence of maternal alloimmunization. In general terms, it carries a high perinatal mortality but the variability of outcome is reflected in its many possible underlying aetiologiesl'2 Historically, Rh alloimmunization accounted for the majority of fetal hydrops cases. The true incidence of non-immune hydrops (NIH) in a population is variable and is probably subiect to regional variation- For example homologous cr-Thalassemia is the commonest cause of hydrops fetalis in South East Asia and arguably the leading cause of NIH worldwide2s. Other causes include cardiac disorders, chromosomal abnormalities, infections, fetal structural anomalies, metabolic disorders and a few maternal conditions suctf as, severe diabetes, severe anemia and severe hypoproteinaemiaa. Metabolic disorders are a recognized cause of NIH but, are relatively rare, examples include; Hurler's syndrome, Gaucher's disease, G6PD deficiency, Niemann pick disease, mucolipidosis and mucopolysacharidosis. Niemann Pick disease is a metabolic disorder that causes the accumulation of Sphingomyelin due to acid Sphingomyelinase deficiency6. It is inherited in an autosomal recessive manner. It is a recognized cause of either fetal hydrops or early and late neonatal death' There are two variants of the disease. Type-A, the acute neuropathic variant, Type-B is the non-neuropathic variant of the disease.