Assessment of intrafamilial clinical variability of poikiloderma with neutropenia by a 10-year follow-up of three affected siblings.

Clericuzio-type poikiloderma with neutropenia is a well-defined nosological entity, but despite a remarkable number of clinical reports, no long term follow-up data has been presented to date regarding patients with this rare condition. Here we describe the results of clinical follow-up of three siblings, one male (Patient 1) and two females (Patients 2 and 3), subsequent to their first clinical and then molecular diagnosis of Clericuzio-type poikiloderma with neutropenia syndrome due to mutation of USB1gene. Patient 1 always expressed the most severe phenotype, while patients 2 and 3 showed an intermediate and mild phenotype, respectively, as observed since their first clinical evaluation. None of the patients developed skin cancer and/or myelodysplastic disorders considering the peripheral haematological findings. Lens opacity, never reported before, was found in two of the three patients. The long term follow-up observations confirm the stability over time of the pronounced intra-familial heterogeneity of clinical manifestations observed prior to and upon molecular diagnosis. We conclude that prolonged follow-up is an adjunct tool to monitor intra-familial variability of PN clinical spectrum which may favour surveillance of more serious complications of the disease among siblings, when a patient-specific clinical expressivity is present.

Combination therapy in a patient with chronic neuronopathic Gaucher disease: a case report.

BACKGROUND: The variants of neuronopathic Gaucher disease may be viewed as a clinical phenotypic continuum divided into acute and chronic forms. The chronic neuronopathic form of Gaucher disease is characterized by a later onset of neurological symptoms and protracted neurological and visceral involvement. The first-choice treatment for nonneuronopathic Gaucher disease is enzyme replacement therapy with recombinant analogues of the deficient human enzyme glucocerebrosidase. Enzyme replacement therapy has been shown to improve hematological and bone manifestations associated with Gaucher disease, but, as with most proteins, recombinant enzymes cannot cross the blood-brain barrier, which prevents effects on neurological manifestations. Substrate reduction therapy with miglustat (N-butyldeoxynojirimycin) inhibits glucosylceramide synthase, which catalyzes the first step in glycosphingolipid synthesis. Because miglustat can cross the blood-brain barrier, it has been suggested that, combined with enzyme replacement therapy, it might be effective in treating neurological symptoms in patients with neuronopathic Gaucher disease. CASE PRESENTATION: We report observed effects of combined enzyme replacement therapy and substrate reduction therapy in a 7-year-old Caucasian boy with neuronopathic Gaucher disease who was homozygous for L444P mutations. He had received enzyme replacement therapy from the age of 18 months, and concomitant miglustat treatment was commenced, with dosing according to body surface area uptitrated over 1 month with dietary modifications when he reached the age of 30 months. He experienced mild diarrhea after commencing miglustat therapy, which decreased in frequency/severity over time. His splenomegaly was reduced, and his hematological values and plasma angiotensin-converting enzyme activity normalized. Plasma chitotriosidase also showed substantial and sustained decreases. After 5 years of combination therapy, the patient showed no signs of neurological impairment. CONCLUSIONS: This case supports the concept that oral miglustat in combination with intravenous enzyme replacement therapy may be beneficial in preventing neurological signs in patients with chronic neuronopathic Gaucher disease. The importance of dietary modifications has also been confirmed. Further follow-up studies are needed to better define the therapeutic effect of combined treatment in this Gaucher disease subtype.

Genetic variants associated with Fabry disease progression despite enzyme replacement therapy.

Enzyme replacement therapy (ERT) has been widely used for the treatment of Fabry disease, a rare X-linked recessive disorder due to absent or reduced activity of lysosomal enzyme α-galactosidase A. It is still unclear why some patients under ERT show disease progression typically with renal, cardiovascular and cerebrovascular dysfunctions. Here, we investigated the involvement of drug absorption, distribution, metabolism, and excretion gene variants in response variability to ERT, genotyping 37 patients with the Affymetrix Drug Metabolizing Enzyme and Transporters (DMET) Plus microarray. We found three single nucleotide polymorphisms in human alcohol dehydrogenase (ADH)4 gene (rs1126670, rs1126671, rs2032349) and one in ADH5 gene (rs2602836) associated with disease progression (p < 0.05). Our data provide a basic tool for identification of patient with ERT non-response risk that may represent a framework for personalized treatment of this rare disease.

Norrbottnian clinical variant of Gaucher disease in Southern Italy.

The Norrbottnian type of Gaucher disease (GD), as described many years ago, is due to a unique neuronopathic variant (c.1448T>G; L444P) that may have appeared during or before the sixteenth century in northern Sweden. It is a well-defined nosological entity with a characteristic course of clinical manifestations. In particular, Norrbottnian patients described in Sweden and Poland seem to share identical clinical histories characterized by the early onset of significant hepatosplenomegaly, often requiring splenectomy at an early age. Neurological involvement generally appears during the first or second decade of life, and includes horizontal gaze palsy, epilepsy, myoclonic movements, ataxia, dementia and cognitive impairment. Osteopenia occurs primarily in the spine, causing a severe and progressive thoracic kyphosis, although the involvement of other skeletal sites cannot be excluded. Here, we report on four Gaucher type 3 patients with Southern Italian ancestry presenting with clinical features and disease progression comparable to those of the 'Norrbottnian' Swedish phenotype, particularly regarding skeletal involvement with poor responsiveness to any therapeutical approach. Although a common ancestry among Southern Italian and Swedish Norrbottnian GD patients could not be investigated, the genotype [L444P]+[L444P] is the most frequently encountered in Southern Italy.