Neonatal pulmonary interstitial glycogenosis in a patient with Hunter syndrome

Abstract

In 2004, we reported on a neonate with pulmonary interstitial glycogenosis (PIG), with favorable outcome at the age of 19 months when the case report was published [8]. However, at the age of 3 years, hepatosplenomegaly and a mild limitation in joint mobility was detected by clinical examination. Hunter syndrome (mucopolysaccharidosis (MPS) type II) was diagnosed. In the following years, the patient presented with frequent upper respiratory infections, moderate hearing loss, and umbilical hernia, common findings in patients with MPS II. At the age of 8 years, the patient’s lung function tests show a severe combined obstructive/restrictive pattern with a forced vital capacity of 70% predicted and a FEV1 of 30% predicted. Infectious exacerbations usually necessitate oral steroid treatment (median of 3 periods annually). The patient receives enzymtherapy (Elaprase® = idursulfase), which stabilized his neurodevelopmental status but not his respiratory problems. It is unclear whether neonatal PIG accompanies MPS II or not. Classically, in MPS II, pulmonary dysfunction manifests primarily by progressive airway disease, frequent upper respiratory tract infections being one of the earliest findings [6]. Clinical features appear between 2 and 4 years of age, newborn infants usually being normal. The biochemical cause is a deficiency in the activity of the lysosomal enzyme, iduronate-2-sulfatase, resulting in reduced degradation of dermatan sulfate and heparan sulfate. Accumulation of these glycosaminoglycans in the soft tissues of the respiratory system leads to narrowing of the trachea, eventually leading to progressive obstructive airway disease, gradually involving the lower airways [5]. Atelectasis and tracheobronchomalacia have also been reported to be associated with MPS II [7]. Glycogen is required to support epidermal mitosis in embryonic respiratory epithelium and other tissues with