A novel loss-of-function mutation in the GNS gene causes Sanfilippo syndrome type D

A novel loss-of-function mutation in the GNS gene causes Sanfilippo syndrome type D: Mucopolysaccharidosis type IIID (MIM 252940) is the least common form of the four subtypes of Sanfilippo syndrome. It is an autosomal recessive lysosomal disorder caused by a deficiency of the N-acetylglucosamine-6-sulphatase (GlcNAc-6S sulphatase, GNS), a hydrolase, which is one of the enzymes involved in heparan sulfate catabolism leading to lysosomal storage. The clinical features of this disorder are progressive neurodegeneration with relatively mild somatic symptoms. Twenty patients have been described in the literature and only seven causative mutations in the GNS gene encoding GlcNAc-6S sulphatase have been reported to date. We present the clinical and molecular results of a newly diagnosed Turkish patient with MPS IIID. We identified the novel homozygous single base pair insertion, c.1226GinsG, which leads to a frame-shift and a premature truncation of the GNS protein (p.R409Rfs21X).

CONCLUSION

This novel mutation provides further evidence that loss-of-function is the underlying pathophysiological mechanism of this rare phenotype.

Association between polymorphisms of endothelial nitric oxide synthase gene (NOS3) and left posterior wall thickness (LPWT) of the heart in Fabry disease

Fabry disease is an X-chromosomal storage disorder due to loss-of-function mutations of the GLA gene encoding the lysosomal enzyme α-galactosidase A. Accumulating glycosphingolipid deposits disturb the function of various cells, in particular that of myocytes, arterial smooth-muscle cells, and vascular endothelium. Hypertrophic cardiomyopathy, for example measured by left posterior wall thickness (LPWT) of the heart, represents a major component of Fabry disease morbidity in adult patients. Endothelium-derived nitric oxide (eNO), produced by eNO synthase (eNOS), is a key regulator of vessel wall function and cardiovascular homeostasis. We analysed the effect of the polymorphisms c.894G > T (p.Glu298Asp) in exon 7 and the 27 bp tandem repeat (VNTR; allele a: 4 and allele b: 5 repeats) in intron 4 of the NOS3 gene, encoding eNOS, on LPWT of 102 patients with Fabry disease. For the association analysis, the distance of each patient's LPWT value from the cohort-specific, age-dependent regression line point (expected values) was used. In the cohort of 46 male patients, LPWT mean value of the group with GG genotype at position c.894 was smaller by 1 mm than that of (GT + TT) (p = 0.058). LPWT of patients with bb was thicker by 1.4 mm than that of (ab + aa) (p = 0.022). In patients with haplotype Ga, a thinner LPWT was seen than in those with Tb (p = 0.006). While no correlation was found between the GLA genotype and LPWT, the difference of 2.44 mm between the relative LPWT mean values of the two extreme NOS3 groups corresponds to the absolute LPWT increase that an average male patient with Fabry disease experiences during about 12 years. These are the first data showing a significant association of non-GLA-derived sequence variants with the cardiac phenotype in Fabry disease that may in part explain the great phenotypic variability of the disease.

[Treatment of complicated proximal segmental tibia fractures with the less invasive stabilization locking plate system]

BACKGROUND

Proximal segmental tibia fractures are rare injuries. Concomitant soft tissue injury, additional articular involvement and ligament injuries, secondary displacement, infection and pseudarthrosis present high demands for the implant and the surgeon. This clinical study was designed to clarify whether Tibia-LISS is a suitable implant for this type of fracture.

MATERIAL AND METHODS

From January 2002 to June 2005, 24 consecutive patients with proximal segmental tibia fractures were evaluated prospectively. All fractures were treated with Tibia-LISS. Follow-up examination was every 4 weeks until fracture healing. The final follow-up examination was at least 1 year after surgery and the average time was 23 months.

RESULTS

Of the 24 patients, 23 could be considered for the follow up examination. On average 3.4 operations per patient were necessary, in 19 patients the fractures (82.6%) healed within 6 months after surgery, 2 deep-seated infections and 5 postoperative misalignments occurred. No patient suffered from secondary loss of reduction but 11 patients (47.8%) suffered from a complicated healing process.

CONCLUSION

Tibia-LISS is a suitable implant for the treatment of proximal segmental tibia fractures with an acceptable rate of complications.

[Metatarsal fractures]

Generally nondisplaced metatarsal fractures can be treated nonoperatively. Fracture angulation of more than 10 degrees or fracture displacement of more than 3-4 mm are a valid indication for open or closed reduction. Fractures of the metatarsal bases are often associated with Lisfranc injury. Special attention must be paid to proximal fractures of the fifth metatarsal (avulsion, Jones, proximal diaphyseal fracture). Dislocated midshaft fractures of the first and fifth metatarsals should be treated operatively to realign foot geometry. Subcapital fracture malalignment causes post-traumatic metatarsalgias. Stress and children's fractures are treated most times nonoperatively.

Correlation between interleukin-6 promoter and C-reactive protein (CRP) polymorphisms and CRP levels with the Mainz Severity Score Index for Fabry disease

OBJECTIVES

Fabry disease is a multisystem disorder with phenotypic heterogeneity only partially explained by genotype. Elevated interleukin-6 (IL-6) plasma levels and C-reactive protein (CRP) serum levels are associated with increased risk and worse outcome of ischaemic events, a serious prognostic sign in Fabry disease.

METHODS

56 patients (34 hemizygous males, 22 females; 5 children) were studied. A promoter polymorphism -174G > C of the IL-6 gene associated with serum IL-6 levels was compared with the Mainz Severity Score Index (MSSI) in patients with Fabry disease. CRP levels and polymorphism 1059 G > C were evaluated as markers of inflammation to ascertain the possibility of an inflammatory mechanism of IL-6. Nonparametric ANOVA, Fisher's exact, Bonferroni, and Hardy-Weinberg (HW) statistics were used.

RESULTS

Mean age of adults = 42 (range 26-58) years; 29 patients received enzyme therapy (ERT). Mean total MSSI = 26.7 (range 14.2-39.2) points, i.e. moderate disease, but females were lower (total 23.4 +/- 12.6 vs 32.2 +/- 13.6). Controls but not patients were in HW equilibrium. Significant correlation existed between all sub-scores of the MSSI and IL-6 genotypes in females but only with three MSSI sub-scores for males. The IL-6 C/C genotype was significantly correlated with the neurological, general and total MSSI sub-scores, generally twofold higher. There were no statistically significant correlations with CRP levels/polymorphisms and MSSI sub-scores nor with IL-6 polymorphisms. CRP levels decreased after ERT in patients with IL-6 G/G or G/C genotypes but increased in patients with C/C (p = 0.003).

CONCLUSIONS

The prevalence of the IL-6 C allele significantly influences MSSI, i.e. clinical severity, especially in females. This is unrelated to IL-6 as a pro-inflammatory marker as demonstrated by lack of correlations with CRP levels and genotypes. IL-6 -174 polymorphic C allele may be a prognostic marker in Fabry disease, especially in females.

[Mucopolysaccharidoses]

Mucopolysaccharidoses are a family of metabolic disorders characterized by a deficiency in the catabolic lysosomal pathways. They are rare, inherited diseases which lead to progressive cellular, tissue and organ damage across a broad spectrum of phenotypes. To prevent irreversible damage early diagnosis is essential. Typical signs and symptoms are the thoracolumbar gibbus, shortened and plumped metacarpal bones, hip dysplasia, deformed ribs and ovoid vertebral bodies. Due to the typical deformation of the pelvis hip dislocation occurs often in childhood. Bilateral carpal tunnel syndrome is frequent. Bone marrow transplantation and enzyme replacement therapy are available. Orthopaedic interventions are based on individual therapeutic decisions and indications.

Phylogenic analysis of the SLA-1 gene variants observed from Korean Jeju pig (Brief Report)

Abstract. The Swine Leukocyte Antigen (SLA) class I consists of SLA-1, SLA-2, and SLA-3 genes (CHARON et al., 2000) that are expressed on the surface of most nucleated cells. Pig organs mainly from miniature pigs have been used in studies on xenotransplantation (SMITH et al., 2005). It is important to understand genetic variations of the SLA-1 gene considering the SLA-mediated immune responses. Collecting information on single nucleotide polymorphisms (SNPs) and alleles of SLA-1 and their phylogenic relationships is important regarding future uses of the Korean Jeju Pig (KJP) in xenotransplantation.

Voxel based analyses of diffusion tensor imaging in Fabry disease

BACKGROUND

Fabry disease (FD) is a lysosomal storage disorder associated with marked cerebrovascular disease. Conventional MRI shows an extensive load of white matter lesions (WMLs) which may already be present at an early stage in the disease.

OBJECTIVE

Investigator independent and sensitive quantification of structural changes in the brain in clinically affected men and women with FD.

METHODS

We performed a voxel based analysis of diffusion tensor images (DTI) in 25 patients with FD and 20 age matched normal controls.

RESULTS

DTI revealed significant increases in cerebral white matter mean diffusivity (MD) in patients with FD, which were pronounced in the periventricular white matter. Even the subgroup of patients without significant WMLs load (n = 18) showed increased diffusivity in the cerebral white matter. In gray matter areas, MD elevation was detected only in the posterior part of the thalamus, independent of the visible pulvinar alterations on T1 weighted images. Voxel based fractional anisotropy measurements did not differ significantly between patients and controls.

CONCLUSIONS

The present study demonstrates the clinical feasibility of voxel based analysis of DTI as a sensitive tool to quantify brain tissue alterations in FD. The pattern of increased brain tissue diffusivity is probably due to microangiopathic alterations, mainly affecting the long perforating arteries.

[Fabry disease: demographic data since introduction of enzyme replacement therapy]

BACKGROUND AND OBJECTIVE

Fabry's disease is a rare, X-chromosome linked recessive lysosomal storage disorder. In its course multiple organ damage occurs, e.g. in skin, nerves, kidneys and heart. The disease not only markedly impairs the quality of life but also shortens life expectancy if untreated. As it is a rare and not widely known disease with considerable variability of its symptoms it is often not or only belatedly diagnosed. Since 2001, enzyme replacement has become available as an option in the causal treatment. It was the aim of this study to analyse the demography and clinical expression of the disease.

PATIENTS AND METHODS

Data were obtained from the Fabry Outcome Survey (FOS), a Europe-wide data bank for the documentation of the disease's clinical course, on 262 patients (130 males, 132 females; mean age 37.5 and 34 years, respectively on entry in the FOS) in Germany, Switzerland and Austria.

RESULTS

Typical symptoms - acroparesthesias, joint pain, hypohidrosis, fever and angiokeratoma - have their onset in childhood (mean age nine years). Symptoms start significantly earlier in males than females. The interval between onset of the first symptoms and establishment of the diagnosis is about 15 years. The severity of the clinical picture, as measured in the POS Mainz severity score index (MSSI), correlates significantly with the person's age (p = 0.0001). Main causes of morbidity and death in Fabry's disease are involvement of the kidneys or heart, the one or other occurring in 75% of patients. 171 patients (38 [65.3%]: 92 males, 79 females) are at present being continually treated with enzyme-replacement (ERT), agalsidase-a, i.e. 70.8% of all male and 59.8 of all female patients in the FOS.

CONCLUSIONS

It is of great importance for the prognosis and quality that Fabry's disease is diagnosed as early as possible and treated adequately before the onset of organ damage. If the listed symptoms by themselves remain unexplained, Fabry's disease should be considered in the differential diagnosis. National and international observational studies, such as the FOS, significantly contribute to gaining important clinical data on this heterogeneous disease.

Direct comparison of enzyme measurements from dried blood and leukocytes from male and female Fabry disease patients

Anderson-Fabry disease is an X-linked disorder that is caused by deficiency of the lysosomal enzyme alpha-galactosidase A. Symptoms include chronic progressive painful small-fibre neuropathy, cornea verticillata, renal failure and heart disease. Interestingly, female heterozygous patients may also show severe symptoms. After clinical suspicion, usually the determination of alpha-galactosidase activity in leukocytes is requested first. Alternatively, an enzymatic assay using dried blood specimens has been described. Dried blood samples require less material and are substantially more stable (several months at room temperature) than whole-blood specimens. To validate the new method and to asses its usefulness for diagnosis of female patients, enzyme activities of alpha-galactosidase, beta-galactosidase and beta-glucuronidase from 78 known Fabry patients were compared (29 males, 47 females) between both materials. In summary, the determination of alpha-galactosidase activity using dried blood and leukocytes as well as the ratio of alpha-galactosidase to beta-glucuronidase in dried blood can improve the diagnostic specificity in cases of female patients who are difficult to identify when only leukocyte enzyme activities are considered.

Fabry disease and the skin: data from FOS, the Fabry outcome survey

BACKGROUND

Fabry disease (also known as Anderson-Fabry disease) is a rare, X-linked lysosomal storage disorder that is characterized by accumulation of globotriaosylceramide throughout a range of tissues in the body.

OBJECTIVES

To ascertain the prevalence and nature of cutaneous manifestations in patients with Fabry disease and to relate these to the severity of systemic manifestations of the disease.

METHODS

We have documented the dermatological features of this disease with reference to data from 714 patients (345 males, 369 females) registered on the Fabry Outcome Survey (FOS), a multicentre European database.

RESULTS

We confirm that the commonest disease manifestation is angiokeratoma. Overall, 78% of males and 50% of females had one or more dermatological abnormality, the commonest being angiokeratoma (66% males, 36% females), hypohidrosis (53% males, 28% females), telangiectasia (23% males, 9% females) and lymphoedema (16% males, 6% females). We demonstrate for the first time that the presence of cutaneous vascular lesions correlates with the severity of the systemic manifestations of the disease (pain, renal failure, cardiac disease, premature cerebrovascular disease) as assessed by a severity scoring system. Although the condition is X linked, there is a surprisingly high prevalence of abnormalities in females.

CONCLUSIONS

The FOS database is a useful epidemiological tool in establishing the variety and relevance of cutaneous manifestations in Fabry disease. The present study confirms that the presence of dermatological manifestations appears to be a marker of greater severity of systemic disease, which emphasizes the importance of the dermatological assessment of these patients.

[Pathophysiological aspects of brain structural disturbances in patients with Fabry disease: literature review]

Fabry Disease (FD) is a rare X-linked lysosomal storage disorder caused by deficiency of alpha-galactosidase A (alpha-GAL) enzyme activity. Neutral glycosphingolipides (esp. Gb3) accumulate in lysosomes of several tissues, particularly in vascular endothelium and smooth muscle cells. Cerebral manifestations that might be mainly due to progressive cerebrovascular dysfunction, are one major and often life-threatening burden of the disease. We reviewed the present literature concerning brain structural alterations in FD and discuss the possibly relevant underlying pathophysiological aspects of these disturbances. Cerebrovascular events (TIA, stroke) occur in FD at a rather early age. In female FD patients who were considered to be less affected "carriers" for a long time, the prevalence of cerebrovascular events seems to be at last as high as in male patients. In structural imaging white matter lesions (WML) can be found frequently even in young FD patients. In a recent study clinically equally affected men and women with FD showed a comparable severity of WML load. Different pathophysiological aspects of cerebral angiopathy and WML development are discussed against the background of current concepts (e. g. accumulation of Gb3 in vascular endothelium with consecutive cell proliferation and luminal stenosis, acceleration of focal intravasal pressure and disturbances of vascular auto-regulation). Pathological increase of pulvinar signal in T1-weighted MRI has also been described in FD. This finding was assumed to be caused by calcification as a consequence of disturbed local circulation. To enhance our knowledge about the relevant neurobiological processes the authors propose a more sensitive and early detection of brain structural changes in FD. New brain structural MRI methods such as diffusion-tensor imaging could provide a pattern of ultrastructural changes even in young patients without visible WML. This strategy could be as well useful for quantification of possible effects of the enzyme replacement therapy on brain structural alterations in FD. Based on recent data a systematic FD-screening by measuring Gb3 in urine of young patients with cryptogenic stroke should be discussed. Basically in such cases FD should be clinically considered.

Hörstörungen bei Morbus Fabry

BACKGROUND

Fabry disease is an X-linked lysosomal storage disease involving deficient activity of alpha-galactosidase A, which leads initially to pain, and later to renal insufficiency, cardiomyopathy and stroke. Until now few details are available on hearing impairment in patients with Fabry disease, and especially few relating to female patients.

PATIENTS AND METHODS

We examined 43 female and 29 male patients. In this study we looked into the question of whether and to what extent patients of both genders are affected by hearing impairment.

RESULTS

Hearing loss is characteristic being more severe at high frequencies frequencies. Overall, 22 female and 15 male patients were found to have suffered a hearing loss. Patients with severe symptoms of Fabry disease usually demonstrate more prominent hearing losses.

CONCLUSIONS

Both men and women with Fabry disease are affected by hearing impairment. It seems that the hearing loss is less marked in female than in male patients. Children with Fabry disease complain of tinnitus more frequently than other children and quite early in the course of the disease.

Enzyme replacement therapy with agalsidase alfa in children with Fabry disease

AIM

To assess the effects of enzyme replacement therapy (ERT) in children with Fabry disease.

METHODS

Safety and efficacy of ERT with agalsidase alfa, 0.2 mg/kg infused over 40 minutes every 2 weeks for 23 weeks, were studied in a multicentre open-label trial in nine boys and four girls. Median age at the start of the study was 11.0 years (range 3.5-18 years).

RESULTS

Fifty-four adverse events were reported in 11 patients. No serious adverse events related to ERT were reported. Twelve of the 54 adverse events were considered possibly or probably related to ERT. Infusion reactions (8 mild, 3 moderate) occurred in four boys, in seven infusions. One boy developed IgG antibodies, although he continued to make good clinical progress. At the end of the study, two of the four boys and the one girl on regular pain medication at baseline had stopped taking analgesics. Brief Pain Inventory (BPI) scores decreased in most patients by week 12 and were sustained until the end of the study. This change was greater in the boys, who had higher (worse) BPI scores at baseline. Pain-related quality of life (QoL) scores also decreased during the study. Plasma globotriaosylceramide concentrations and urinary globotriaosylceramide:sphingomyelin ratios decreased after 12 and 23 weeks of therapy, particularly in the boys. Increases in sweat volume were recorded in three out of five of the boys and in one of two girls tested after 23 weeks of treatment.

CONCLUSION

ERT with agalsidase alfa in children with Fabry disease is well tolerated and, in the short term, appears to decrease pain and to improve pain-related QoL.

Recombinant human acid [alpha]-glucosidase: major clinical benefits in infantile-onset Pompe disease

BACKGROUND

Pompe disease is a progressive metabolic neuromuscular disorder resulting from deficiency of lysosomal acid alpha-glucosidase (GAA). Infantile-onset Pompe disease is characterized by cardiomyopathy, respiratory and skeletal muscle weakness, and early death. The safety and efficacy of recombinant human (rh) GAA were evaluated in 18 patients with rapidly progressing infantile-onset Pompe disease.

METHODS

Patients were diagnosed at 6 months of age and younger and exhibited severe GAA deficiency and cardiomyopathy. Patients received IV infusions of rhGAA at 20 mg/kg (n = 9) or 40 mg/kg (n = 9) every other week. Analyses were performed 52 weeks after the last patient was randomized to treatment.

RESULTS

All patients (100%) survived to 18 months of age. A Cox proportional hazards analysis demonstrated that treatment reduced the risk of death by 99%, reduced the risk of death or invasive ventilation by 92%, and reduced the risk of death or any type of ventilation by 88%, as compared to an untreated historical control group. There was no clear advantage of the 40-mg/kg dose with regard to efficacy. Eleven of the 18 patients experienced 164 infusion-associated reactions; all were mild or moderate in intensity.

CONCLUSIONS

Recombinant human acid alpha-glucosidase is safe and effective for treatment of infantile-onset Pompe disease. Eleven patients experienced adverse events related to treatment, but none discontinued. The young age at which these patients initiated therapy may have contributed to their improved response compared to previous trials with recombinant human acid alpha-glucosidase in which patients were older.

[Complex proximal humerus fractures--management with a humeral head prosthesis? Clinical and radiological results of a prospective study]

BACKGROUND

Proximal humerus fractures are one of the most common fractures in elderly patients. In the treatment of complex proximal humerus fractures, primary hemiarthroplasty is still discussed controversially. The present study was undertaken to evaluate the results of primary hemiarthroplasty in the treatment of proximal humerus fractures with a modular prosthesis (EPOCA, Fa. Argomedical, Gifhorn, Germany).

MATERIAL AND METHODS

A prospective study of 24 patients with complex humerus fracture (NEER: IV/4, V/4, VI/4, and head split fracture) was performed from August 2000 to December 2002. Mean age was 75.6 years (range: 52-92); 18 patients were seen for follow-up after 0.5 and 1 year, respectively. The Constant-Murley score (max. 100 points) and the UCLA Rating System (max. 35 points) were calculated for functional assessment of the operated shoulder.

RESULTS

Fifteen patients (83%) were pain free 1 year after the operation. The Constant-Murley score improved from 52 (+/-17) to 56 (+/-18) at the second follow-up after 1 year. On the contralateral side a score of 86 (+/-10) was assessed (p<0.05 vs operated side). Correspondingly, shoulder function according to the UCLA Rating System improved [25 (+/-4); 27 (+/-5)].

CONCLUSIONS

Osteoporotic bone of older patients often may not permit stable internal fixation of complex proximal humerus fractures. In these situations primary hemiarthroplasty is the treatment of choice.

Os acetabuli in femoro-acetabular impingement: stress fracture or unfused secondary ossification centre of the acetabular rim?

Ossicles located at the acetabular rim are generally referred to as unfused secondary ossification centres and are named "os acetabuli". They are also observed in severely dysplastic hips, where they are considered as fatigue fractures of the acetabular rim due to overload. In a retrospective study, we evaluated the radiographs of 495 patients, who were treated surgically for femoro-acetabular impingement. In 18 hips (15 patients) a large osseous fragment at the anterolateral acetabular rim was found. All patients presented radiographically with a femoral head showing an aspherical extension producing a "cam" impingement. Sixteen hips had a retroverted acetabulum, indicating anterior overcover. Preoperative MRIs available in 12 patients showed the presence of a fragment composed of labrum, articular cartilage and bone. The gap between the stable acetabulum and the rim fragment had a vertical orientation. All patients had been exposed to a physically demanding profession or contact sport and in 15 hips no memorable traumatic episode was present. The mechanism leading to this acetabular rim fragment is thought to be fatiguing due to femoro-acetabular impingement. The aspheric portion of the head is jammed into the acetabulum and with time causes a stress fracture of the retroverted portion of the acetabulum. True "Os acetabuli" are morphologically similar, but the orientation of the cartilaginous growth plate is more parallel to the joint surface, in contrast to the hips in the current study, where the separation line was perpendicular to the joint surface. The clinical importance is that the presence of an acetabular rim fragment in the non-dysplastic hip must raise suspicion of femoro-acetabular impingement.;

Hearing loss in Fabry disease: data from the Fabry Outcome Survey

Hearing loss is a common symptom in Fabry disease, but neither its natural course nor its aetiology has been defined precisely. The aim of this study was to provide a detailed epidemiological description of hearing impairment in patients in the Fabry Outcome Survey (FOS), which is the largest available database of Fabry patients. Questionnaires were completed by 566 Fabry patients, of whom 316 reported ear-related symptoms. Pure-tone audiograms from 86 patients, performed before starting enzyme replacement therapy, were analysed and compared with age- and sex-specific normal values (International Organization for Standardization, ISO 7029). When compared to an age-matched population (ISO 7029), 74% of patients had a threshold elevated above the 95th centile in at least one tested frequency. All frequencies were affected to a similar degree. However, only 14 patients (16%) were clinically affected by hearing impairment according to the age-independent World Health Organization (WHO) classification (mean threshold at 0.5, 1 and 2 kHz worse than 25 dB). Hearing loss was sensorineural in 63 patients (73%) of whom 7 patients (8%) had also a conductive component. One patient had a purely conductive hearing loss. Episodes of sudden hearing loss seemed to occur more frequently than in the general population. Men were affected earlier and more severely than women. Hearing in Fabry disease is significantly worse than in an age-matched general population but leads to clinically relevant hearing impairment in only 16% of cases. It resembles accelerated presbycusis with an additional Fabry-specific strial-type hearing loss.

Hyperhidrosis: a new and often early symptom in Fabry disease. International experience and data from the Fabry Outcome Survey

Hypohidrosis is a classic feature of Fabry disease; in contrast, hyperhidrosis has only been rarely described. The aim of the study is to characterise the baseline descriptive data on hyperhidrosis (frequency, age at onset, sex ratio and outcome with and without enzyme replacement therapy) in hemizygous male and heterozygous female patients with Fabry disease. We describe case histories of five patients with Fabry disease and hyperhidrosis seen at three different centres. We have also analysed a cohort of 21 paediatric patients in the UK and a large European cohort of patients enrolled in the Fabry Outcome Survey (FOS). Five patients (three female, two male) with hyperhidrosis were originally identified, although each had additional symptoms related to Fabry disease. The age at onset of hyperhidrosis was less than 18 years in four cases. In the cohort of 21 paediatric patients (12 female, nine male), one female had hyperhidrosis; the age at onset of this symptom was 11 years. In the FOS cohort, 66 of 714 patients with Fabry disease had hyperhidrosis (44 of 369 females, 11.9%; 22 of 345 males, 6.4%). The female predominance was observed in seven of nine countries from which data were analysed. Hyperhidrosis is an increasingly recognised feature of the Fabry disease phenotype. It is more prevalent in females than in males and often appears in childhood or adolescence. The efficacy of enzyme replacement therapy on this recently recognised symptom should be assessed.

Agalsidase alpha and hearing in Fabry disease: data from the Fabry Outcome Survey

Fabry disease is an X-linked lysosomal storage disorder characterized by multi-organ dysfunction, including hearing loss - mainly sensorineural. The recent introduction of enzyme replacement therapy (ERT) has resulted in improvements in renal and cardiac function, pain and quality of life. One study has also suggested small improvements in high-frequency hearing. In this paper, we study the effect of ERT on hearing in patients in the Europe-wide database - the Fabry Outcome Survey (FOS). Twenty-six patients in FOS had pure-tone audiometry performed up to 6 months before starting ERT with agalsidase alpha and after a median of 12 months of treatment. We assessed changes in hearing thresholds, expressed as deviations from the 50th centile of the normal population (International Organization for Standardization ISO 7029) to correct for age-related non-specific hearing deterioration. Hearing did not change significantly in ears with normal hearing (less than 10 dB deviation from the 50th centile of ISO 7029) or those with severe hearing loss (more than 40 dB deviation from the 50th centile of ISO 7029) at baseline. In ears with a mild or moderate hearing loss at baseline, hearing thresholds, expressed as deviations from the normal 50th centile, improved significantly by 4-7 dB at most frequencies (P < 0.05). Agalsidase alpha stabilizes, and possibly improves, hearing in Fabry patients who have not already progressed to severe hearing loss. Further follow-up of these patients will determine the longer-term effects of ERT.

Enzyme replacement therapy and renal function in 201 patients with Fabry disease

AIM

Fabry disease is a rare lysosomal storage disorder caused by deficient activity of alpha-galactosidase A, resulting in progressive cellular accumulation of glycolipids, which may ultimately result in endstage renal disease. We examined the effects of enzyme replacement therapy (ERT) with Agalsidase-alpha on renal function using data from a large international database, the Fabry Outcome Survey (FOS).

METHODS

This analysis was based on 1,040 serum creatinine measurements in 201 patients with Fabry disease, aged 20 - 60 years, with serum creatinine concentrations of less than 2 mg/dl and duration of ERT of up to 4.7 years. Both pretreatment and treatment data were used to examine independent predictors of changes in serum creatinine. In a second approach longitudinal serum creatinine measurements from 1 year before treatment, at baseline and 1 and 2 years after the start of treatment were analyzed in 20 patients with chronic kidney disease (CKD) Stage 2 and 3.

RESULTS

We found an independent negative association between serum creatinine and time on Agalsidase-alpha treatment (p < 0.05). Renal function declined significantly (p < 0.05) in the year before treatment. After 1 year of treatment, however, the decline in estimated glomerular filtration rate had been halted, and renal function was preserved for up to 2 years.

CONCLUSIONS

In conclusion, ERT with Agalsidase-alpha is associated with decrease of serum creatinine and may prevent the deterioration of renal function in patients with Fabry disease.

Acetabular dome retroversion: radiological appearance, incidence and relevance

Interest in acetabular version arose from the study of unstable developmental dysplastic hips (DDH). Initial studies and clinical observations described the dysplastic hip as being excessively anteverted. Doubts on this view arose from analysis of complications such as persistent posterior subluxation after acetabular reorienting procedures. Computed tomography fails to determine conclusively whether or not the dysplastic acetabulum is abnormally anteverted. Controversy evolves from different methods of measuring and from the fact that the acetabular opening gradually spirals from mild anteversion proximally to increasing anteversion distally. This renders the measurement of version dependent on pelvic inclination and the level of the transverse CT scan slice. On an orthograde pelvic radiograph, both pelvic inclination and rotation can be controlled. Therefore, acetabular version is best estimated based on the relationship of the anterior and posterior acetabular rims to each other on an orthograde pelvic radiograph. Acetabular retroversion has been found to be a characteristic feature of specific hip disorders such as post-traumatic dysplasia, proximal femoral focal deficiency and bladder exstrophy. In addition, acetabular retroversion has been described in DDH as well as in dysplastic hips in the context of neuromuscular and genetic disorders. Iatrogenic acetabular retroversion can also result from corrective pelvic osteotomies in childhood. Finally, retroverted acetabula may be found in otherwise nondysplastic hips. The relevance of acetabular retroversion is twofold: First, it demands a more individualized approach to acetabular dysplasia because the presence of retroversion will affect the manner in which the corrective osteotomy should be done. Second, the long-term effect of acetabular retroversion is harmful.

[Femoroacetabular impingement: trigger for the development of coxarthrosis]

Femoroacetabular impingement (FAI) is frequent; the estimated prevalence ranges between 10 and 15%. Our 10-years experience strongly suggests that FAI leads to osteoarthritis. Isolated acetabular or femoral abnormalities are rare, even though in women acetabular and in men femoral abnormalities predominate. Normal radiographs do not exclude the presence of FAI. Symptoms are related to the degree of deformity and occur earlier in the presence of activities requiring high levels of motion. The majority of patients with FAI are under the age of 40 years. In contrast to impingement in total hip replacement, the natural hip is under much higher constraint, not allowing to escape from impingement-induced shear forces by subluxation or complete dislocation. FAI-induced shear forces due to an aspherical femoral head/neck (cam type) are therefore high, causing outside-in damage with cleavage lesions of the acetabular cartilage by forced flexion and internal rotation. The cartilage of the femoral head remains initially intact, which cannot be explained by the classic concept of osteoarthritis. After the femoral head has migrated into the acetabular cartilage defect, vertical forces contribute to the further course of osteoarthritis. Tears between the labrum and cartilage, as seen by MRI, are not avulsions of the labrum from the cartilage but rather outside-in avulsions of the cartilage from the labrum. In acetabular overcoverage (pincer type) the labrum is the first structure to fail and acetabular cartilage damage develops thereafter. The treatment of FAI in patients under the age of 40 years is aimed at joint preservation. The clinical result is worse in the presence of significant cartilage damage. Therefore, early appreciation of FAI and timely therapeutic intervention as well as professional and athletic adjustment are important if osteoarthritis is to be prevented.

Effects of enzyme replacement therapy on pain and health related quality of life in patients with Fabry disease: data from FOS (Fabry Outcome Survey)

BACKGROUND

Fabry disease is an X linked lysosomal storage disease caused by deficiency of the lysosomal enzyme alpha-galactosidase A. This leads to accumulation of globotriaosylceramide in nearly all tissues, including the blood vessels, kidney, myocardium, and nervous system. Symptoms often begin in childhood and include acroparaesthesia, with burning or tingling pain that spreads from the extremities to more proximal sites.

AIMS

This study set out to evaluate pain and its influence on quality of life in patients with Fabry disease receiving enzyme replacement therapy (ERT) with agalsidase alfa.

METHODS

Data were obtained from the Fabry Outcome Survey. Pain was measured using the Brief Pain Inventory (BPI), and health-related quality of life (HRQoL) was documented with the European Quality of Life Questionnaire (EQ-5D).

RESULTS

The mean (SD) score for "pain at its worst" on the BPI prior to ERT was 5.1 (2.7). One year after commencement of ERT, this had improved by 0.5, and improved by a further 0.6 after 2 years (p<0.05). Similar statistically significant improvements were seen for "pain on average" and "pain now" after 2 years of ERT. The mean HRQoL utility score prior to ERT was 0.66 (0.32). After 12 months of treatment with agalsidase alfa, this had improved to 0.74 (0.26; p<0.05); this improvement was maintained after 2 years.

CONCLUSIONS

ERT with agalsidase alfa significantly reduces pain and improves quality of life in patients with Fabry disease.

[Bilateral post-traumatic acetabular dysplasia]

Traumatic disruption of the acetabular triradiate cartilage is an infrequent injury. When it occurs in early childhood, it may lead to growth changes in acetabular morphology. The morphology of this kind of acetabular dysplasia is uniform and differs significantly from that seen in classic developmental dysplasia of the hip. We present a case of bilateral post-traumatic acetabular dysplasia, which to our knowledge has not been reported. The morphology and the symptoms of impingement and periacetabular osteotomy of the hip joint are discussed.