Awareness of Fabry disease among rheumatologists--current status and perspectives

What should rheumatologists know about Gaucher disease and Fabry disease? Connecting the dots for an overview

Gaucher and Fabry diseases are lysosomal storage disorders in which deficient enzyme activity leads to pathological accumulation of sphingolipids. These diseases have a broad phenotypic presentation. Musculoskeletal symptoms and pain complaints are frequently reported by patients. Thus, rheumatologists can be contacted by these patients, contributing to the correct diagnosis, earlier indication of appropriate treatment and improvement of their prognosis. This review describes important concepts about Gaucher and Fabry diseases that rheumatologists should understand to improve patients' quality of life and change the natural history of these diseases.

[Multisystem lesions in orphan diseases: rheumatological aspects of Fabry's disease. Case report]

Fabry-Andersen disease is a genetically determined, progressive disease related to lysosomal storage diseases, linked to the X chromosome, characterized by impaired glycosphingolipid metabolism, due to the deficiency or absence of the enzyme α-galactosidase A. Fabry disease is a multisystem disease and is characterized by damage to vital organs - kidneys, heart, brain, with the occurrence of complications that cause an unfavorable prognosis. Autoinflammation mechanisms with signs of chronic inflammation are involved in the pathogenesis of the disease. One of the features of Fabry disease are clinical manifestations in the form of arthralgia, fever, skin lesions, which are similar to rheumatological diseases. The article presents a clinical observation of the classical type of Fabry disease with multiple organ manifestation, which required differential diagnosis with rheumatological diseases. Rheumatologists are specialists who are involved in the early diagnosis of Fabry disease, so they should have a high awareness of this sphingolipidosis.

Frequency of Fabry disease in a juvenile idiopathic arthritis cohort

BACKGROUND

Fabry disease (FD) is a rare, X-linked, multisystemic lysosomal storage disorder (LSD) that results from a deficiency in the hydrolase alpha-galactosidase A (⍺-GalA). During childhood, classic FD symptomatology is rare. The majority of children may show non-specific symptoms, including in the musculoskeletal system. The prevalence of FD among juvenile idiopathic arthritis (JIA) patients is unknown.

OBJECTIVE

This study aimed to identify the frequency of FD in a JIA cohort, characterizing early clinical symptoms, enzyme titers, and GLA genotyping.

METHODS

Children with JIA followed in a tertiary Children Hospital cohort were selected. Clinical, laboratory and familiar information were recorded. Molecular genetic testing to detect GLA gene mutations was performed in girls and enzymatic analysis in boys.

RESULTS

In 89 patients (56.2% female, age at disease onset: 8.93 ± 4.35 years), one male (1.12%) patient presented pathogenic mutation in GLA gene, c.1244 T > C p.L415P, one female patient had a variant of uncertain significance c.38C > T (p.Ala13Val). Three additional (3.4%) patients had the enzymatic activity of alpha-galactosidase slightly decreased. We observed the presence of intronic variants in 44.44% of patients in our cohort: c.1000-22C > T; c.370-81_-77del; c.640-16A > G; c.10C > T; c.548-125C > G and c.-12G > A. These variants and their combination were associated with clinical symptoms in our cohort.

CONCLUSIONS

The incidence of FD in our cohort was 1.12%. Intronic variants were associated with symptoms previously described in the literature. Screening for FD in JIA may be a reasonable strategy for those with an atypical pattern of pain.

Higher rate of rheumatic manifestations and delay in diagnosis in Brazilian Fabry disease patients

BACKGROUND

Fabry disease (FD) is an X-linked lysosomal disorder due to mutations in the GLA gene resulting in defective enzyme alpha-galactosidase A. FD patients are frequently misdiagnosed, commonly for rheumatic diseases. Determining pathogenicity of a mutation depends of in silico predictions but mostly on available clinical information and interpretation may change in light of evolving knowledge. Similar signs and symptoms in carriers of GLA gene genetic variants of unknown significance or of benign variants may hamper diagnosis. This study reviews rheumatic and immune-mediated manifestations in a cohort of Brazilian FD patients with classic mutations and also in subjects with GLA gene A143T and R118C mutations. Misdiagnoses, time to correct diagnosis or determination of GLA gene status, time to treatment initiation and reasons for treatment prescription in A143T and R118C subjects are reviewed.

METHODS

Genotype confirmed classic FD patients (n = 37) and subjects with GLA gene mutations A143T and R118C (n = 19) were referred for assessment. Subjects with R118C and A143T mutations had been previously identified during screening procedures at hemodialysis units. All patients were interviewed and examined by a rheumatologist with previous knowledge of disease and/or mutation status. A structured tool developed by the authors was used to cover all aspects of FD and of common rheumatic conditions. All available laboratory and imaging data were reviewed.

RESULTS

Thirty-seven consecutive FD patients were interviewed - 16 male / 21 female (mean age: 43.1 years) and 19 consecutive subjects with GLA gene mutations R118C and A143T were evaluated - 8 male / 11 female (mean age: 39.6 years); 15 [R118C] / 4 [A143T]. Misdiagnosis in FD patients occurred in 11 males (68.8%) and 13 females (61.9%) of which 10 males and 9 females were previously diagnosed with one or more rheumatic conditions, most frequently rheumatic fever or "rheumatism" (unspecified rheumatic disorder). Median time for diagnosis after symptom onset was 16 years (range, 0-52 years). Twenty-two patients were treated with enzyme replacement therapy (ERT) - 13 male and 9 female. Median time to ERT initiation after FD diagnosis was 0.5 years (range, 0-15 years). Rheumatic manifestations occurred in 68.4% of R118C and A143T subjects. Two subjects had been prescribed ERT because of renal disease [R118C] and neuropsychiatric symptoms [A143T].

CONCLUSION

Misdiagnoses occurred in 64.8% of FD patients, most frequently for rheumatic conditions. Median time for correct diagnosis was 16 years. Rheumatic manifestations are also frequent in subjects with GLA gene R118C and A143T mutations. These results reinforce the need to raise awareness and increase knowledge about Fabry disease among physicians, notably rheumatologists, who definitely have a role in identifying patients and determining disease burden. Decision to start treatment should consider expert opinion and follow local guidelines.

The Influence of Patient-Reported Joint Manifestations on Quality of Life in Fabry Patients

Fabry disease, a lysosomal storage disorder, is a rare inborn error of metabolism caused by deficiency of the enzyme alpha galactosidase A and resulting accumulation of globotriaosylceramide. The symptoms of Fabry disease are heterogeneous including renal failure, cardiac hypertrophy, and stroke and may not be well recognized by non-specialist physicians. Patients with milder, later onset of disease often have a delay in diagnosis.Fabry patients may suffer significant neuropathic pain in the extremities (acroparasthesia) but the degree to which musculoskeletal symptoms contribute to total pain and disability is unknown. Here, we present a questionnaire study focusing on joint manifestations and their impact on daily life of patients with Fabry disease.Seventy-seven patients with Fabry disease and age-matched healthy controls (49 female and 28 male) took part in a survey focused on joint problems, pain, disability, and quality of life. Joint pain and swelling were reported by 43% of male and 39% of female Fabry patients. Analysis by age group showed higher prevalence of joint problems and decreased quality of life, in terms of mobility, activity, pain, and anxiety, in Fabry patients younger than 50 years compared to healthy controls. Female Fabry patients had higher fatigue scores compared to control subjects. Fabry patients reported problems with vigorous daily activities and gripping.Musculoskeletal symptoms are common in Fabry patients and contribute to overall pain and decreased quality of life. Awareness of Fabry disease by physicians may be raised to ensure timely diagnosis of this rare disease.

Significant improvement in Fabry disease podocytopathy after 3 years of treatment with agalsidase beta

BACKGROUND

Fabry disease is an X-linked lysosomal disorder caused by decreased activity of α-galactosidase A (GLA). Consequent accumulation of globotriaosylceramide (GL-3) in lysosomes results in damage to a variety of organs, including the kidneys. Enzyme replacement therapy (ERT) is an effective treatment, but whether it should be started before organ damage is evident is a matter of debate.

CASE DIAGNOSIS/TREATMENT

A 10-year-old boy who complained of severe sole pain for 3 years had been misdiagnosed with juvenile idiopathic arthritis. Further investigations revealed decreased GLA activity and a M1T mutation in the GLA gene causing protein truncation, suggestive of Fabry disease. Despite normal renal function and urinalysis, renal biopsy showed abnormal structure, with marked accumulation of GL-3 in podocytes, partial effacement of foot processes and irregularly reduced expression of nephrin in the slit diaphragm. After 1 year of ERT with 1 mg/kg agalsidase beta once every 2 weeks, his pain had resolved with ERT combined with carbamazepine and pregabalin. After 3 years of the ERT, repeat biopsy showed little renal GL-3 deposition, resolution of foot process effacement, and a dramatic improvement in nephrin expression.

CONCLUSIONS

There may be a window of opportunity in which pain and renal injury can be addressed in the early stages of Fabry disease. Early initiation of ERT should therefore be considered for children with Fabry disease.

Understanding the gastrointestinal manifestations of Fabry disease: promoting prompt diagnosis

Fabry disease is a rare X-linked lysosomal storage disease characterized by the dysfunction of multiple systems, including significant gastrointestinal involvement such as diarrhea, abdominal pain, early satiety and nausea. The gastrointestinal symptoms of Fabry disease are thought to be due to neuropathic and myopathic changes leading to symptoms of dysmotility that are encountered in many other disorders. The gastrointestinal symptoms can often be one of the presenting signs of the disease in childhood, but can be misdiagnosed by gastroenterologists for many years due to their nonspecific presentation. As the chief treatment for Fabry is enzyme-replacement therapy that has been shown to stabilize and possibly reverse disease course, recognition of these symptoms and early diagnosis in an attempt to prevent progression with treatment, is critical.

Musculoskeletal manifestations of Fabry disease: A retrospective study

OBJECTIVES

Fabry disease is a rare X-linked metabolic disorder characterized by a deficiency in the enzyme alpha-galactosidase A. Both males and females can be affected. The main presenting symptom is pain in the extremities, whereas at a more advanced stage, the manifestations include hypertrophic cardiomyopathy, cardiac dysrhythmia, proteinuria, chronic kidney dysfunction, stroke, and hearing loss. When not diagnosed and treated, Fabry disease causes early death. No studies specifically designed to describe the musculoskeletal manifestations of Fabry disease are available.

METHODS

We conducted a single-center retrospective study of patients receiving follow-up at a Fabry disease referral center. We described the musculoskeletal manifestations and analyzed the differential diagnoses.

RESULTS

Our study included 40 patients belonging to 20 families, including 25 females with a mean age of 44.2 years (range, 20-76 years) and 15 males with a mean age of 40.1 years (range, 16-61 years). Mean age at the diagnosis of Fabry disease was 37.2 years (range, 7-71 years) in the females and 26.9 years (range, 9-51 years) in the males. Specific enzyme replacement therapy was given to 10 (40%) females and 12 (80%) males. Musculoskeletal manifestations were as follows: past or present pain in the extremities (13 females and 10 males), combined in some patients with vasomotor disorders in the extremities and telangiectasia; exercise intolerance (12 females and 12 males); osteoporotic fractures (2 brothers aged 45 and 44 years, respectively); osteoporosis (3 females, aged 57, 63, and 75 years, respectively), which contributed to death in the oldest patient; osteopenia (2 females aged 38 and 47 years, respectively; and 1 male aged 43 years); Charcot foot and lymphedema with serious infectious complications (4 males older than 40 years), with avascular osteonecrosis of the lower limbs in 2 cases; toe amputations (3 cases); bilateral lower-limb amputation (1 case); abnormally slender lower limbs (5 females and 8 males); acute gout (3 males with severe chronic kidney failure); and carpal tunnel syndrome (1 female and 1 male, both younger than 40 years). Mistaken diagnoses that were made at an early stage, contributing to delay the identification of Fabry disease, included rheumatic fever (2 females and 2 males), growing pains (2 males), pain with paralysis (1 female), chilblains of the lower limbs (1 female), and erythermalgia (1 female). In adulthood, the following mistaken diagnoses were made: Sjögren's syndrome and/or sicca syndrome (6 females), systemic sclerosis (1 male), dysautonomia (1 female), and familial Mediterranean fever (1 female).

CONCLUSION

The diagnosis of Fabry disease is usually delayed, due to confusion with more common disorders. Musculoskeletal manifestations may constitute the presenting symptoms. Past or present pain in the extremities is typical. Osteoporosis may develop early and become severe. Together with the family history, the presence of musculoskeletal manifestations can lead to the correct diagnosis by prompting alpha-galactosidase assays in males and genetic testing in females. Fabry disease is often responsible for musculoskeletal manifestations, of which the most common are pain in the extremities and osteoporosis. These manifestations can be inaugural and lead to diagnostic wanderings. They require specific treatment strategies.