Endocrine disorders in patients with Fabry disease: insights from a reference centre prospective study

Context Fabry Disease (FD) is a rare X-linked storage disease characterised by a-galactosidase A deficiency and diffuse organ accumulation of glycosphingolipids. Enzyme replacement and chaperone therapies are only partially effective. It remains unclear if FD-related endocrine disorders contribute to the observed morbidity. Objective To investigate the function of the endocrine system in patients with FD. Design We conducted an observational prospective study from 2017 to 2020. Setting and patients We included 77 patients with genetically confirmed FD (27 men, 20/27 Classic, 7/26 Late Onset phenotype, 50 women, 41/50 and 9/50 respectively), who are systematically followed by our reference centre. Results 36/77 (46.8%) patients had VitD deficiency (25(0H)VitD <20 μg/L) despite the fact that 19/36 (52.8%) were substituted with cholecalciferol. Only 21/77 (27.3%) patients had normal VitD levels without VitD substitution. 11/77 (14.3%) had significant hypophosphatemia (p < 0.80 mmol/L). Three new cases (3.9%) of subclinical, two (2.6%) of overt and six (7.8%) of known hypothyroidism were identified. Of note, men had significantly higher renin levels than women [61.4 (26.1–219.6) vs.25.4 (10.9–48.0) mU/L, p = 0.003]. There were no major abnormalities in adrenal, growth and sex-hormone axes. Patients of Classic phenotype had significantly higher High-Density Lipoprotein Cholesterol (HDL-C) levels (p = 0.002) and in men those levels were positively correlated with globotriaosylsphingosin (Lyso-Gb3) values. 10/77 (13%) of the patients were underweight. Conclusions VitD supplementation should be considered for all patients with FD. Thyroid screening should be routinely performed. Malnutrition should be prevented or treated, particularly in Classic phenotype patients. Overall, our data suggest that FD specialists should actively seek and diagnose endocrine disorders in their patients.

Increased Prevalence of Fractures in Congenital Adrenal Hyperplasia: A Swedish Population-Based National Cohort Study

Context Low bone mineral density has been reported in individuals with congenital adrenal hyperplasia (CAH), but the prevalence of fractures is unclear. Objective To study the prevalence of fractures in CAH. Design, Setting, and Participants: Patients with CAH (n=714, all 21-hydroxylase deficiency) were compared with controls matched for sex and year and place of birth (n=71,400). Data were derived by linking National Population-Based Registers. . Main Outcome Measures Number and type of fractures. Results Mean age was 29.8±18.4 years. Individuals with CAH had more fractures compared to controls (23.5% vs. 16.1%, OR 1.61, 95%CI 1.35-1.91), and this was found in both sexes (females: 19.6% vs. 13.3%, OR 1.57, 95%CI 1.23-2.02; males: 28.7% vs. 19.6%, OR 1.65, 95%CI 1.29-2.12). Fractures were significantly increased in patients born before the introduction of neonatal screening but not in those born afterwards. Any major fracture associated with osteoporosis (spine, forearm, hip or shoulder) was increased in all individuals with CAH (9.8% vs. 7.5%, OR 1.34, 95%CI 1.05-1.72). The highest prevalence of fractures was seen in SV phenotype and I172N genotype while non-classic phenotype and I2 splice genotype did not show increased prevalence. A transport accident as a car occupant and fall on the same level were more common in patients with CAH, both sexes, than in controls. Conclusions Patients with CAH had an increased prevalence of both any fracture and fractures associated with osteoporosis (both sexes) but not for patient neonatally screened. We conclude that fracture risk assessment and glucocorticoid optimization should be performed regularly.

Health-Related Quality of Life in Fabry Disease: A Cross-sectional International Multicenter Study

BackgroundFabry disease (FD) is a rare X-linked lysosomal storage disorder caused by α-galactosidase A (α-Gal A) deficiency. The progressive accumulation of globotriaosylceramide results in life-threatening complications, including renal, cardiac, and cerebrovascular diseases. In order to improve health care of FD-patients, knowledge of its predictors is important. The aim of our study was to evaluate health-related quality of life (HrQol) in FD and to identify its independent determinants by exploring a wide range of demographic, social and clinical parameters.ResultsIn this cross-sectional multicenter study, 124 adult patients with FD were recruited at three specialized European centers in Germany and Switzerland. Demographics, social status and clinical parameters as well as data on HrQol (EQ5D, EQVAS) and depression were collected by means of self-reporting questionnaires. HrQol and its predictors were evaluated by univariate and multivariate regression analyses.Study population consisted of 72 female and 52 male FD patients (median age 48yrs) of whom 87.9% (N=109) were on enzyme replacement therapy (ERT) (68.8% [N= 75] were on agalsidase α and 31.2% [N=34] on agalsidase β). Univariate analysis revealed various factors reducing HrQol, such as age>40 years, classic phenotype, organ involvement (kidney and heart disease, stroke/transient ischemic attack, gastrointestinal disturbances), depression, and burning limb pain. However, only the following factors were identified as independent predictors of decreased HrQol: classic phenotype, kidney and heart disease, stroke/TIA, depression, and burning limb pain. ERT was an independent determinant of increased HrQol.ConclusionsModifiable factors, such as burning limb pain and depression identified as independent predictors of HrQol-deterioration should be addressed in programs aiming to improve HrQol in FD. A multidisciplinary approach is essential in FD-patients since diverse organ involvement prominently compromises HrQol in affected patients. Our findings that the classic phenotype is a strong predictor of HrQol worsening.

Insulin-Mediated Substrate Utilization in Women with the Different Phenotypes of PCOS: Role of Androgens

Context/Objective Few studies have explored in vivo insulin action on substrate utilization in women with PCOS. In particular, no data are available in women with different PCOS phenotypes. The aim of the study was to evaluate insulin action on glucose (Gox) and lipid (Lox) oxidation, non-oxidative glucose metabolism (Gnonox), and serum free fatty acid (FFA) in different PCOS phenotypes. Subjects One hundred and eighty-seven non-diabetic women with PCOS, diagnosed according to the Rotterdam criteria. Data from a historical sample of 20 healthy women were used as reference values. Design Whole body substrate utilization data were obtained by the hyperinsulinemic euglycemic clamp associated with indirect calorimetry. Serum androgens were assessed by liquid chromatography-mass spectrometry and equilibrium dialysis. Results During hyperinsulinemia, the increase of Gox (Δ Gox), Gnonox, as well as the suppression of Lox (Δ Lox) and serum FFA (Δ% FFA) were altered in each PCOS phenotype. Moreover, Gnonox and Δ% FFA were lower in women with the classic phenotype than in those with the ovulatory or the normoandrogenic phenotypes, and Δ Gox was lower in women with the classic than in those with the ovulatory phenotype. In multivariate analysis fat mass and free testosterone were independent predictors of Δ Gox, Gnonox and Δ% FFA, whereas only fat mass predicted Δ Lox. Conclusions In women with PCOS, regardless of their phenotypes, insulin-mediated substrate utilization is impaired. This phenomenon is greater in subjects with the classic phenotype. Free testosterone plays an independent role on insulin action abnormalities on glucose and lipid metabolism.

Mosaicism in Fragile X syndrome: A family case series

Fragile X syndrome (FXS) has a classic phenotype, however its expression can be variable among full mutation males. This is secondary to variable methylation mosaicisms and the number of CGG triplet repeats in the non-coding region of the Fragile X Mental Retardation 1 ( FMR1) gene, producing a variable expression of the Fragile X Mental Retardation Protein (FMRP). Here we report a family with several individuals affected by FXS: a boy with a hypermethylated FMR1 mutation and a classic phenotype; a man with an FMR1 gene mosaicism in the range of premutation (PM) and full mutation (FM), who has a mild phenotype due to which FXS was initially disregarded; and the cases of four women with a FM and mosaicism. This report highlights the importance of DNA molecular testing for the diagnosis of FXS in patients with developmental delay, intellectual disability and/or autism due to the variable phenotype that occurs in individuals with FMR1 mosaicisms.

Late diagnsis of Fabry disease at the stage of cardiac involvement

A clinical case report of late diagnosis (in relation to clinical manifestation) of the classic phenotype of Fabry disease in patient with cardiac involvement: phenocopy of hypertrophy cardiomyopathy, cardiac arrhythmias and conduction abnormalities.

Novel GLA T194A variant causes Fabry disease

Fabry disease (FD) is an X-linked, systemic lysosomal deposition disease caused by alpha-galactosidase A (AGAL) enzyme deficiency deriving out of changes on the GLA gene. Though several mutations have been described, one must consider that even a specific mutation may present with variable clinical expression within the same family. Typically described as a disease that affects hemizygous men with no residual AGAL activity, we describe a novel FD mutation (first case of GLA T194A variant worldwide) in a 49-year-old woman presenting with a classic phenotype of FD. The patient investigation highlighted a previously not described mutation in exon 4 of the GLA gene, as for the substitution of threonine for alanine. The same mutation was identified in her children, one of them presenting with end-stage kidney disease (ESKD) in early adulthood.

Evaluation of Cerebral Microvascular Regulatory Mechanisms with Transcranial Doppler in Fabry Disease

Background: Fabry disease (FD) causes cerebrovascular disease (CVD) even if asymptomatic, and this is why it is important to identify non-invasive methods to monitor the disease. We evaluated the usefulness of the cerebral autoregulation, vasoreactivity, and neurovascular coupling assessed by transcranial Doppler (TCD) in FD. Methods: Ten adult patients with classic phenotype FD, without clinical expression of CVD, and ten healthy controls, were included. We monitored cerebral blood flow velocity with TCD in the middle and posterior cerebral arteries, blood pressure, heart rate, and non-invasive expired carbon dioxide (CO2). Cerebral autoregulation was calculated from the spontaneous oscillations of blood pressure, cerebral vasoreactivity through CO2 inhalation and hyperventilation and neurovascular coupling by the flow velocity change to visual stimulation. Results: FD male patients showed blunted vasoreactivity in posterior circulation (0.70 ± 0.36%/mmHg vs. 1.09 ± 0.18%/mmHg CO2, p = 0.01) and impaired neurovascular coupling (overshoot 15 ± 2.9% vs. 28 ± 6.1%, p < 0.01). Cerebral autoregulation was similar to controls. Conclusion: Male patients with FD classic phenotype and hitherto clinical expression of CVD already show impairment of cerebral vasoreactivity and neurovascular coupling. It supports the notion of an early dysfunction of cerebral microvascular in a presymptomatic stage of CVD in FD and that TCD could be useful in its assessment.

Aarskog-Scott syndrome: clinical and molecular characterisation of a family with the coexistence of a novel FGD1 mutation and 16p13.11-p12.3 microduplication

Aarskog-Scott syndrome (AAS), also known as facio-genital dysplasia or faciodigitogenital syndrome, is a rare genetic disorder clinically characterised by facial, limb and genitalanomalies. Although also autosomal dominance and recessive patterns have been reported, up to now, only an X linked form associated to mutations of the FGD1 gene has been recognised as causative for this syndrome.In this case report, we describe a large Italian family in which three members across three generations show classical features of the syndrome. The youngest patient, the proband, and his mother were both molecularly studied and characterised for the not previously reported variant c.1828C>T (p. Arg610*) in the FGD1 gene but with the classic phenotype of AAS. Additionally, both the proband and his mother present a 2.5 Mb 16p13.11-p12.3 microduplication, a genetic variant still unclear for the phenotypic consequences: the co-occurrence of the two rare conditions is discussed for the possible clinical significance.

Agalsidase beta treatment slows estimated glomerular filtration rate loss in classic Fabry disease patients: results from an individual patient data meta-analysis

Background Fabry disease is a rare, X-linked genetic disorder that, if untreated in patients with the Classic phenotype, often progresses to end-stage kidney disease. This meta-analysis determined the effect of agalsidase beta on loss of estimated glomerular filtration rate (eGFR) in the Classic phenotype using an expansive evidence base of individual patient-level data. Methods The evidence base included four Sanofi-Genzyme studies and six studies from a systematic literature review. These were restricted to Classic Fabry patients meeting the eligibility criteria from Phases III and IV agalsidase beta trials, including 315 patients (161 treated). Linear regression was first used to model annual change in eGFR for each patient and the resulting annualized eGFR slopes were modelled with treatment and covariates using quantile regression. These results were then used to estimate median annualized eGFR change in agalsidase beta treated versus untreated groups. Results Imbalances across treatment groups were found in baseline age, sex and proteinuria, but not in the use of renin–angiotensin system blockers. The adjusted model suggests that treated (agalsidase beta) patients experienced a slower median eGFR decrease [2.46 mL/min/1.73 m2/year slower; 95% confidence interval (CI) 0.63–4.29; P = 0.0087] than comparable untreated patients. The median eGFR decrease was 2.64 mL/min/1.73 m2/year slower (95% CI 0.53–4.78; P = 0.0141) in treated Classic males. Conclusions Using an expansive evidence base and robust modelling approach, these data indicate that agalsidase beta-treated patients with the Classic phenotype conserve their renal function better than untreated patients.