Chronic renal failure, dialysis, and renal transplantation in Anderson-Fabry disease

Sudden onset of nephrotic syndrome in an asymptomatic Fabry patient: a case report

Background

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by the mutation of the GLA gene, encoding the α-galactosidase, which is responsible for the catabolism of neutral glycosphingolipids. Microalbuminuria or low-grade proteinuria, and continuously progressive renal failure are common manifestations in FD males. However, sudden onset of nephrotic syndrome in FD, is rarely reported.

Case report

A 32-year-old Chinese man was admitted to our hospital because of sudden onset of generalized edema due to nephrotic syndrome. He denied hypohidrosis, nocturia, and any history of episodic hand or foot pain. A few scattered angiokeratoma can be found on the low back skin on examination. Except for the similar locating pattern of angiokeratoma, no evident abnormality was found in the laboratory work up and physical examination of his younger brother. The patient was diagnosed with FD companying with minimal change disease by renal biopsy. Genetic analysis on our patient and his sibling revealed a nonsense GLA gene variant (c.707G > A, p.Trp236*), which has been previously reported in FD. Immunotherapy alone (steroids and tacrolimus), but without enzyme replacement therapy, much improved the massive proteinuria. Follow up to date, his 24-h urine protein is stable at about 0.5 g, and renal function keeps normal.

Conclusion

Sudden onset of nephrotic syndrome, although rare, may occur in FD, even as the primary renal manifestation, but this usually suggests additional renal disease. Immunosuppressive treatment should be considered in such FD patient companying with nephrotic syndrome.

Variable phenotypic presentations of renal involvement in Fabry disease: a case series

Fabry disease is an X-linked genetic deficiency in the alpha-galactosidase enzyme resulting in intracellular accumulation of glycosphingolipids and multisystem organ dysfunction. Typically 50% of males and 20% of affected females have renal involvement, ranging from proteinuria or reduced renal function, renal parapelvic cysts and progressive renal disease ultimately requiring transplantation or dialysis. The phenotypic presentation of Fabry disease is incredibly varied and will even vary between family members with the same confirmed genetic mutation. In a cohort of patients affected by Fabry disease in the North East of England we examine the different phenotypic presentations of eight index cases (6 male, 2 female) with predominantly renal disease and the renal manifestations within their family members. The mean age of presentation was 40 years of age (range 23-59 years). Various multisystem manifestations were observed including cardiac, neurological, cerebrovascular and skin involvement. Two of the male index patients reached end stage renal disease (ESRD) requiring renal replacement therapy. Two female index patients had phenotypes limited to hypertension and proteinuria at presentation and the remaining patients had either stable or progressive chronic kidney disease at the time of diagnosis. We demonstrate the need for a high index of suspicion in order to consider Fabry disease as a diagnosis and the importance of cascade genetic screening to identify affected family members so that treatment can be initiated in a timely fashion.

[Combined heart and kidney transplantation in Fabry's disease: Long-term outcomes in two patients]

INTRODUCTION

Fabry disease is a lysosomal storage disorder linked to an alpha-galactosidase A deficiency that can lead to heart and kidney failure. There is little data about the prognosis of patients who undergo a combined heart and kidney transplantation.

CASE REPORTS

Two brothers who were diagnosed with Fabry disease after the age of 30 years underwent a combined heart and kidney transplantation at respectively 49 and 42 years of age because of a severe hypertrophic cardiomyopathy with end stage renal failure. They are alive respectively 4 and 9 years after the transplantation. No recurrence of the disease in the transplanted organs has been found.

CONCLUSION

Combined heart and kidney transplantation in Fabry disease is an efficient therapy for the cardiomyopathy and kidney failure. Its prognosis can be good when the patients are carefully selected. However, an early diagnosis is critical in order to avoid a procedure associated with a high perioperative mortality.

Non-neuronopathic lysosomal storage disorders: Disease spectrum and treatments

Distinctive facial features, hepatosplenomegaly or cardiomyopathy with or without associated skeletal dysplasia are clinical manifestations that may be suggestive of an underlying lysosomal storage disorder (LSD), However, these features may not be evident in certain subtypes associated primarily with central nervous system involvement. Age at onset can be broad, ranging from infancy to adulthood. Diagnosis may be delayed, as manifestations may be slow to evolve (taking months to years), particularly in those with later (adult-)onset, and in isolated cases (i.e., those without a prior family history). Diagnosis of individual subtypes can be confirmed using a combination of biochemical and molecular assays. In a few LSDs, treatment with hematopoietic stem cell transplantation, enzyme replacement or substrate reduction therapy is available. Symptomatic and palliative measure may enhance quality of life for both treatable and currently untreatable cases. Genetic counseling is important, so patients and their families can be informed of reproductive risks, disease prognosis and therapeutic options. Investigations of underlying disease mechanisms are enhancing knowledge about rare diseases, but also other more common medical conditions, on account of potential convergent disease pathways.

A missense mutation of the α-galactosidase A gene in a Chinese family of Fabry disease with renal failure

BACKGROUND

Fabry disease (FD) is a rare disease due to an X-linked recessive inborn error of glycosphingolipid metabolism resulting from the mutations of the α-galactosidase A (α-gal A) gene. FD is rare in Chinese and the data on clinic and genetic features of FD is still limited.

METHODS

In this study, the α-gal A gene of a Chinese family diagnosed with FD was analyzed for mutations and the genetic features of FD in this family were presented.

RESULTS

The α-gal A activity of the proband in this family was 0.03 nmol/ml/h in the whole blood. By PCR amplification and sequencing of the α-gal A gene exons, a single C-to-T transition was identified in codon 112 of exon 2. This C-to-T transition, mapping to position 334 in the cDNA of the α-gal A gene, was a missense mutation predicting a substitution of arginine to cysteine (p.R112C), which disrupts the normal activity of α-gal A enzyme. No further mutations were found in other exons of the α-gal A gene. In contrast to previous reports, in this family, all of the five male patients developed end-stage renal failure due to this missense mutation.

CONCLUSIONS

These findings suggest that the missense mutation, p.R112C, in α-gal A gene ablates its activity and results in the development of FD with the renal damage.

Frequency of Fabry disease in male and female haemodialysis patients in Spain

BACKGROUND

Fabry disease (FD), an X-linked lysosomal storage disorder, is caused by a reduced activity of the lysosomal enzyme alpha-galactosidase A. The disorder ultimately leads to organ damage (including renal failure) in males and females. However, heterozygous females usually present a milder phenotype with a later onset and a slower progression.

METHODS

A combined enzymatic and genetic strategy was used, measuring the activity of alpha-galactosidase A and genotyping the alpha-galactosidase A gene (GLA) in dried blood samples (DBS) of 911 patients undergoing haemodialysis in centers across Spain.

RESULTS

GLA alterations were found in seven unrelated patients (4 males and 3 females). Two novel mutations (p.Gly346AlafsX347 and p.Val199GlyfsX203) were identified as well as a previously described mutation, R118C. The R118C mutation was present in 60% of unrelated patients with GLA causal mutations. The D313Y alteration, considered by some authors as a pseudo-deficiency allele, was also found in two out of seven patients.

CONCLUSIONS

Excluding the controversial D313Y alteration, FD presents a frequency of one in 182 individuals (0.55%) within this population of males and females undergoing haemodialysis. Moreover, our findings suggest that a number of patients with unexplained and atypical symptoms of renal disease may have FD. Screening programmes for FD in populations of individuals presenting severe kidney dysfunction, cardiac alterations or cerebrovascular disease may lead to the diagnosis of FD in those patients, the study of their families and eventually the implementation of a specific therapy.

Screening for Fabry disease in patients with chronic kidney disease: limitations of plasma alpha-galactosidase assay as a screening test

BACKGROUND AND OBJECTIVES

Fabry disease is a progressive X-linked disorder of glycosphingolipid metabolism that typically presents in childhood and progresses to heart failure and renal failure in adulthood. This study sought to determine the prevalence of Fabry disease in a multiethnic male chronic kidney disease population, involving dialysis-dependent, non-dialysis-dependent, and transplant patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 499 patients were screened with assay of alpha-galactosidase activity using fluorometric enzyme assay on plasma prepared from fresh heparinized blood, followed by leukocyte alpha-galactosidase activity in the subset of patients with plasma alpha-galactosidase activity below the second percentile (corresponding to a value <3.0 nmol/h per ml plasma).

RESULTS

This study did not identify any new cases of Fabry disease; however, repeat testing of some of the study patients identified three limitations of the plasma enzyme assay that is commonly used as a high throughput screening method for Fabry disease: (1) False-negative results can occur; (2) these false-negative results are not prevented by use of inhibitors of alpha-galactosidase B activity; and (3) considerable intraindividual variation in plasma alpha-galactosidase levels reduces the discriminatory power of the screening test.

CONCLUSION

Clinicians need to be aware that screening using plasma will fail to detect some patients with Fabry disease.