Type 2 Gaucher disease: the collodion baby phenotype revisited

Perinatal lethal Gaucher disease: a distinct phenotype along the neuronopathic continuum

Gaucher disease, the inherited deficiency of glucocerebrosidase, is characterized by significant genetic and phenotypic heterogeneity. At the extreme end of the phenotypic continuum is the perinatal lethal variant, typically presenting in utero or during the neonatal period as hydrops and/orcongenital ichthyosis, with severe and progressive neurological involvement. Insights from the null-allele Gaucher mouse model contributed to the identification of this distinct phenotype, which has unique epidermal involvement. While multiple mutations are encountered, many affected infants are homozygous for recombinant alleles. The diagnosis is often missed due to the early lethality and the failure to recognize the association between lysosomal disorders and hydrops fetalis. The incidence of severe perinatal Gaucher disease may prove more common than currently appreciated with greater physician awareness of the disorder.

Intrauterine onset of acute neuropathic type 2 Gaucher disease: identification of a novel insertion sequence

A subset of patients with type 2 Gaucher disease is characterized by intrauterine onset of rapidly progressive neuropathic disease, arthrogryposis, hydrops fetalis and in some cases restrictive dermopathy. beta-Glucocerebrosidase (beta-glucosidase) activity is usually low or undetectable. In most cases death ensues either in-utero or within hours or days after birth. We report on an infant born to non-consanguineous parents of Caucasian origin presenting at birth with hydrops, arthrogryposis, severe respiratory distress, hepatosplenomegaly, and liver failure. Death occurred within several hours after delivery and autopsy revealed typical Gaucher cells in multiple organs in combination with severe apoptotic neurodegeneration throughout the brain. beta-Glucocerebrosidase activity was 1% of the norm in fibroblasts and a novel heterozygous insertion c.1515_1516insAGTGAGGGCAAT was identified by genomic sequencing and an insertion-specific seminested PCR. In addition, molecular studies revealed a previously described in type 1 Gaucher disease missense mutation c.476G --> A which results in a heterozygous substitution of R120Q. Our observations confirm considerable genotypic heterogeneity in patients with type 2 Gaucher disease. The transheterozygous combination of a mutation, previously described in type 1 Gaucher disease, together with a newly identified insertion may result in this severe phenotype.

Gaucher disease: complexity in a "simple" disorder

Gaucher disease, the recessively inherited deficiency of the enzyme glucocerebrosidase and the most common sphingolipidosis, has both non-neurological and neuronopathic forms and a continuum of diverse clinical manifestations. Studies of genotype-phenotype correlations reveal significant genotypic heterogeneity among clinically similar patients, and vastly different phenotypes among patients with the same mutations. The region surrounding the glucocerebrosidase gene (GBA) on chromosome 1q is particularly gene-rich, with a highly homologous pseudogene sequence 16 kb downstream. Recombination events within the GBA locus contribute to the etiology of some mutations in Gaucher disease. Studies of patients with Gaucher disease and atypical manifestations, including parkinsonism, myoclonic epilepsy, cardiac involvement and collodion skin, seek to define other genetic or environmental factors contributing to the phenotypes. Recent reports demonstrating an association between Gaucher disease and parkinsonism provide an example of heterozygosity for a Mendelian disorder acting as a risk factor for a complex disease. There are rare patients with Gaucher disease and differing genotypes who develop early onset, treatment-refractory parkinsonism. Neuropathology in a group of these patients showed alpha-synuclein-reactive Lewy bodies in brain regions specifically associated with Gaucher disease. Family studies of these probands suggested that the incidence of parkinsonism might be more frequent in obligate heterozygotes. In a complementary finding, the examination of GBA in autopsy samples from individuals with sporadic Parkinson disease identified alterations in the GBA sequence in 14% of the cohort. These studies provide evidence that altered glucocerebrosidase may contribute to a vulnerability to parkinsonism. Moreover, this research demonstrates how insights from rare, single gene disorders like Gaucher disease can provide a window into the etiology of more common, multifactorial genetic diseases.

Homozygous loss of a cysteine residue in the glucocerebrosidase gene results in Gaucher's disease with a hydropic phenotype

Acute neuronopathic Gaucher's disease is classically considered to be a disease of late infancy, but also includes a spectrum of variant phenotypes such as perinatal lethal hydrops, or the collodian baby phenotype in the newborn period. These extreme phenotypes are frequently associated with recombinant alleles, nonsense mutations and rare missense mutations. In this report, we present a family with multiple incidence of a hydrops where Gaucher's disease was confirmed. Mutational analysis revealed the homozygosity for the missense mutation C16S, which is located in exon 3 and results in the loss of a cysteine residue. This genotype would be predicted to result in virtually zero enzyme activity.

Novel mutation, L371V, causing multigenerational Gaucher disease in a Lebanese family

We have identified six individuals over three generations within a Lebanese-Arab family affected with Gaucher disease. This family is unusual and informative because affected members are homozygous for a previously unidentified mutation, L371V. Clinical symptoms begin in early childhood and progress to moderately severe involvement by young adulthood. There is significant anemia, thrombocytopenia, and bony involvement, but no mental deterioration. The phenotype is more severe than the phenotype observed in the common mutation associated with type 1 Gaucher disease, N370S. It is unknown whether L371V is a private mutation limited to this family, or will prove to be a common mutation within the Lebanese population.

Perinatal-lethal Gaucher disease

Gaucher disease is a lysosomal storage disease caused by glucocerebrosidase deficiency. Although purely visceral in most cases, some Gaucher disease patients have neurological signs. Signs of Gaucher disease appear after a symptom-free period, except in rare cases with fetal onset. The description of such cases was based mainly on single reports and siblings. We report here a series of perinatal-lethal Gaucher disease cases highlighting the specificity of this phenotype. We retrospectively studied eight original cases of proven Gaucher disease with fetal onset. Non-immune hydrops fetalis was present in all cases but one, and associated with hepatosplenomegaly, ichthyosis, arthrogryposis, and facial dysmorphy. The similarities between our cases and 33 previously described cases allow us to better delineate the perinatal-lethal Gaucher disease phenotype. Hydrops fetalis, in utero fetal death and neonatal distress are prominent features. When hydrops is absent, neurological involvement begins in the first week and leads to death within three months. Hepatosplenomegaly is a major sign, and associated with ichthyosis, arthrogryposis, and facial dysmorphy in some 35-43% of cases. Perinatal-lethal Gaucher disease is a specific entity defined by its particular course and signs that are absent in classical type 2 Gaucher disease. Our study provides clues to the diagnosis of this likely underdiagnosed condition, which must be biochemically confirmed in order to propose appropriate genetic counselling.

Gaucher's disease: identification of novel mutant alleles and genotype-phenotype relationships

A sequencing protocol for the acid beta-glucosidase (GCase) gene (GBA) was developed using a long-range PCR template. This protocol has an advantage of greater DNA yields over similar strategies. Seven Gaucher's disease patients had four novel and five other rare alleles. A non-pseudogene in-frame deletion (g.2600-2602delTAC) and a new complex mutation (null allele) were identified in Gaucher's disease type 1, i.e. the g.2600-2602delTAC deletion is associated with the non-neuronopathic variant. An F251L allele was found in a baby with the collodion skin phenotype. Three mutant alleles were identified in a single primary family with type 3. The patients' father at 45 years is healthy and is heteroallelic for the G202R and E326K alleles. Family studies indicated that E326K is in trans to G202R and L444P, and that isolated E326K is non-pathogenic in this family. A rare mutation R257Q was identified in a type 2 patient, providing an association with neuronopathic disease. A genotype L444P/L444P was noted in a 22-year-old non-neuronopathic patient. Complete gene sequencing showed a new complex allele consisting of L444P and g.7741T > C in the 3' UTR. Three additional complex alleles also involved the 3' UTR. Complete gene characterization in Gaucher's disease should allow greater insights into the correlation of specific alleles with phenotype.

Collodion baby associated with asymmetric crying facies: a case report

Collodion baby is a distinct subset of neonatal erythroderma that can be a clinical marker for a variety of underlying abnormalities. The phenotype includes parchment-like hyperkeratosis, pseudocontractures, ectropion, eclabium, absence of eyebrows, and sparse hair. Asymmetric crying facies is caused by congenital hypoplasia or agenesis of the depressor anguli oris muscle. Associations of this facial defect with major congenital anomalies have been reported, most commonly in the cardiovascular system, less frequently involving the genitourinary, musculoskeletal, cervicofacial, and respiratory systems, and rarely the endocrine system. We report a newborn with a collodion membrane and asymmetric crying facies. To the best of our knowledge, this association has not been previously published.

Correlation among genotype, phenotype, and biochemical markers in Gaucher disease: implications for the prediction of disease severity

Gaucher disease is a lysosomal storage disorder characterized by a deficiency of the enzyme acid beta-glucosidase. The clinical manifestations of Gaucher disease are highly variable, and although certain genotypes are often associated with mild or severe symptoms, a defined correlation between genotype and phenotype does not exist. Identification of biochemical markers characteristic of pathology may be of use in predicting the progression of the disease state. In this study the relationship among genotype, glycolipid substrates, lysosomal proteins, and the clinical manifestations of Gaucher disease has been evaluated. Plasma glycolipids were analyzed using electrospray ionization-tandem mass spectrometry. Lysosomal-associated membrane protein-1 (LAMP-1) and saposin C were determined by immunoquantification. Patients with Gaucher disease were shown to have an increased 16:0-glucosylceramide/16:0-lactosylceramide ratio and elevated concentrations of LAMP-1 and saposin C in plasma. A general relationship was found to exist among the 16:0-glucosylceramide/16:0-lactosylceramide ratio, LAMP-1 and saposin C levels, and patient phenotype, providing a refinement of the genotype-phenotype correlation. These findings have major implications for the diagnosis, prediction of disease severity, and monitoring of therapy in patients with Gaucher disease.