Investigating genotype-phenotype relationships in Rett syndrome using an international data set

BACKGROUND

Rett syndrome is an uncommon neurodevelopmental disorder with an incidence of 1:9,000 live female births. The principal genetic cause was first reported in 1999 when the association with mutations in the methyl-CpG-binding protein 2 (or MECP2) gene was identified. This study uses data from a large international database, InterRett, to examine genotype-phenotype relationships and compares these with previous findings in a population-based cohort.

METHOD

The data set for these analyses was derived from a subset of InterRett cases with subject information collected from the family, the clinician, or both. Individual phenotypic characteristics and clinical severity using three scales were compared among those with eight known recurrent pathogenic MECP2 mutations as well as those with C-terminal deletions (n = 272).

RESULTS

Overall, p.R270X and p.R255X were the most severe and p.R133C and p.R294X were the mildest mutations. Significant differences by mutation were seen for individual phenotypic characteristics such as hand use, ambulation, and language.

CONCLUSIONS

This multicenter investigation into the phenotypic correlates of MECP2 mutations in Rett syndrome has provided a greater depth of understanding than hitherto available about the specific phenotypic characteristics associated with commonly occurring mutations. Although the modifying influence of X inactivation on clinical severity could not be included in the analysis, the findings confirm clear genotype-phenotype relationships in Rett syndrome and show the benefits of collaboration crucial to effective research in rare disorders.

Vanishing white matter disease associated with progressive macrocephaly

Vanishing white matter disease (VWM) is one of the most frequent inherited childhood leukoencephalopathies. Five genes have been implicated in this disease ( EIF2B1-5), which encode the five subunits of translation initiation factor eIF2B. The disease has an autosomal recessive mode of inheritance. The age of onset and clinical severity vary widely. The diagnosis is based on magnetic resonance imaging (MRI) findings and is confirmed by molecular studies. We describe an affected female patient with a common and a novel mutation of the EIF2B5 gene, who demonstrated a progressive neurological and radiological deterioration. An unusual feature was her striking macrocephaly. She had an early clinical onset at two years of age and is currently still alive at 26 years of age.

Roselle (Hibiscus sabdariffa) seed oil is a rich source of gamma-tocopherol

The antioxidant potential of roselle (Hibiscus sabdariffa L.) extracts was studied. Different plant organs, including seeds, stems, leaves, and sepals, were analyzed with respect to their water-soluble antioxidant capacity, lipid-soluble antioxidant capacity, and tocopherol content, revealing that roselle seeds are a good source of lipid-soluble antioxidants, particularly gamma-tocopherol. Roselle seed oil was extracted and characterized, and its physicochemical parameters are summarized: acidity, 2.24%; peroxide index, 8.63 meq/kg; extinction coefficients at 232 (k(232)) and 270 nm (k(270)), 3.19 and 1.46, respectively; oxidative stability, 15.53 h; refractive index, 1.477; density, 0.92 kg/L; and viscosity, 15.9 cP. Roselle seed oil belongs to the linoleic/oleic category, its most abundant fatty acids being C18:2 (40.1%), C18:1 (28%), C16:0 (20%), C18:0 (5.3%), and C19:1 (1.7%). Sterols include beta-sitosterol (71.9%), campesterol (13.6%), Delta-5-avenasterol (5.9%), cholesterol (1.35%), and clerosterol (0.6%). Total tocopherols were detected at an average concentration of 2000 mg/kg, including alpha-tocopherol (25%), gamma-tocopherol (74.5%), and delta-tocopherol (0.5%). The global characteristics of roselle seed oil suggest that it could have important industrial applications, adding to the traditional use of roselle sepals in the elaboration of karkade tea.

TH1/TH2 cytokine release pattern during in vivo cytomegalovirus disease in solid organ transplantation

BACKGROUND

Cytomegalovirus (CMV) disease is associated with an increased net immunosuppressive state in solid organ transplant recipients, leading to more bacterial and fungal infections. The release of pro- and anti-inflammatory cytokines could be one of the responsible factors.

METHODS

We prospectively included all patients undergoing solid organ transplantation between April and November 2004. During follow-up, plasma samples were collected in the immediate postsurgical period, at the first and second months, at the time of maximum antigenemia during CMV disease, and at 6 months posttransplantation. We determine the levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-10. Log-transformed data were compared by a nonparametric Wilcoxon test for related variables.

RESULTS

During the study period, we monitored 146 recipients of solid organ transplantation: 77 kidneys, 8 kidney-pancreas, 46 liver, 11 heart, 2 liver-kidney, and 2 heart-kidney. No differences were observed between the TNF-alpha and IL-10 levels in the immediate postsurgical period or during CMV disease. TNF-alpha and IL-10 levels during CMV disease were higher than levels during the first month (mean TNF-alpha first month = 12.71 pg/mL vs CMV disease = 22.71 pg/mL, P = .028; mean IL-10 first month = 3.47 pg/mL vs CMV disease = 19.2 pg/mL, P = .018). Th1/Th2 ratio (measured as TNF-alpha/IL-10) was 1.75 in the immediate postsurgical period, 7.5 during the first month, 1.86 at the time of CMV disease, and 4.61 at the sixth month. The difference in Th1/Th2 ratio during CMV disease and in the first month was statistically significant (P = .043).

CONCLUSION

During CMV disease, we observed an increase in TNF-alpha and IL-10 release, which was similar to that during the postsurgical period. An imbalance toward an anti-inflammatory pattern was noted in these two periods. This could reflect a cooperative factor increasing the net state of immunosuppression during CMV disease.

Creatine transporter deficiency: Prevalence among patients with mental retardation and pitfalls in metabolite screening

OBJECTIVES

To report the prevalence of creatine transporter deficiency in males with mental retardation and to study whether a protein-rich food intake might be a potential diagnostic pitfall.

DESIGN AND METHODS

We determined creatine/creatinine ratio in urine samples from 1600 unrelated male patients with mental retardation and/or autism. Urine creatine was analyzed by HPLC-MS/MS.

RESULTS

Thirty-three of 1600 cases showed increased urine creatine/creatinine ratio. Four out of these thirty-three cases were definitively diagnosed with creatine transporter deficiency, while the other 29 were false positive results. Significantly higher values were observed for urine Cr/Crn ratio in healthy volunteers after a meal based on beef or oily fish as compared to eggs, pasta or salad (Wilcoxon test: p<0.005).

CONCLUSIONS

False positive results may be observed in biochemical screening for creatine transporter deficiency, and they may be due to intake of meals rich in creatine prior to urine samples analysis.

Secondary abnormalities of neurotransmitters in infants with neurological disorders

Neurotransmitters are essential in young children for differentiation and neuronal growth of the developing nervous system. We aimed to identify possible factors related to secondary neurotransmitter abnormalities in pediatric patients with neurological disorders. We analyzed cerebrospinal fluid (CSF) and biogenic amine metabolites in 56 infants (33 males, 23 females; mean age 5.8mo [SD 4.1mo] range 1d-1y) with neurological disorders whose aetiology was initially unknown. Patients were classified into three clinical phenotypes: epileptic encephalopathy, severe motor impairment, and non-specific manifestations. All patients showed normal results for screening of inborn errors of metabolism. We report clinical, neuroimaging, and follow-up data. Among the patients studied, 10 had low homovanillic acid (HVA) levels and in four patients, 5-hydroxyindoleacetic acid (5-HIAA) was also reduced. Patients with neonatal onset had significantly lower levels of HVA than a comparison group. HVA deficiency was also associated with severe motor impairment and the final diagnosis related to neurodegenerative disorders. 5-HIAA values tended to be decreased in patients with brain cortical atrophy. The possibility of treating patients with L-Dopa and 5-hydroxytryptophan, in order to improve their neurological function and maturation, may be considered.

Impact of Valganciclovir Prophylaxis on the Development of Severe Late-Cytomegalovirus Disease in High-Risk Solid Organ Transplant Recipients

BACKGROUND

With the introduction of prolonged prophylaxis with valganciclovir in cytomegalovirus (CMV) donor/recipient serodiscordance (D+/R-) patients, concerns about a high incidence of late and invasive CMV disease associated with mortality have emerged. We compared the characteristics of CMV disease in D+/R- patients receiving prolonged valganciclovir prophylaxis with R+ patients.

METHODS

We prospectively followed all solid organ transplant recipients from January 2004 to December 2005. CMV prophylaxis with valganciclovir or ganciclovir was administered as follows: donor- recipient serodiscordance (D+/R-), 12 weeks; induction with antithymocyte globulin or acute rejection episodes requiring steroid pulses, 15 to 30 days; and CMV R+ double kidney-pancreas, 15 days. Transplant characteristics and the development of CMV disease variables were collected for all patients. We defined 2 groups according to the risk of CMV disease: CMV donor/recipient mismatch (D+/R-) and recipient CMV-positive (R+) groups.

RESULTS

During the study period we performed 481 solid organ transplantations: 237 kidney, 34 kidney-pancreas, 157 liver, 38 heart, 13 liver-kidney, and 2 heart-kidney. Overall, 36 patients developed CMV disease (7.5%). CMV donor-recipient mismatch (D+/R-) was associated with a greater risk of CMV disease compared with CMV-positive recipients (16% vs 7%; P = .036). Prophylaxis against CMV was longer in the D+/R- group (mean days 73 vs 15; P < .001). CMV disease appeared later in the D+/R- than in R+ group (mean days 123 vs 59; P < .001). We observed a trend toward a lower incidence of tissue-invasive CMV disease among the D+/R- group compared with the R+ group without significance (14% vs 41%; P = .382). Three patients died in the first 30 days after the onset of CMV disease, all of them in the R+ group.

CONCLUSIONS

In our setting, high-risk patients (D+/R-) receiving prolonged prophylaxis with valganciclovir developed later CMV disease, but this was neither more tissue-invasive nor more life-threatening than in the R+ group.

Folate receptor autoantibodies and spinal fluid 5-methyltetrahydrofolate deficiency in Rett syndrome

Rett syndrome was associated with low cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF) in 42-50% of European patients whereas approximately 93% of the patients from North-America had a normal CSF 5MTHF status. We determined the CSF folate status in Rett patients living in North- and South-Western Europe and measured serum folate receptor (FR) autoantibodies of the blocking type to explain the reduced folate transport across the choroid plexus. Irrespective of their MECP2 genotype and despite normal plasma folate values, 14 of 33 Rett patients (42%) had low CSF folate levels. Blocking FR autoantibodies were found in 8 of the Rett patients (24%), 6 of whom had low CSF folate levels. FR autoimmunity was primarily found within the group of Rett patients with low CSF folate status with a higher incidence in North-Western Europe. In Rett patients from North-America 74 of 76 girls had higher folate values in both serum and CSF than European patients. The food folate fortification in North-America may account for the higher folate levels and may prevent CFD in these Rett patients. FR autoimmunity occurred predominantly in Rett patients from North-Western Europe and may contribute to cerebral folate deficiency (CFD).

Clinical, biochemical and molecular aspects of cerebellar ataxia and Coenzyme Q10 deficiency

Coenzyme Q(10) (CoQ) deficiency is an autosomal recessive disorder presenting five phenotypes: a myopathic form, a severe infantile neurological syndrome associated with nephritic syndrome, an ataxic variant, Leigh syndrome and a pure myopathic form. The third is the most common phenotype related with CoQ deficiency and it will be the focus of this review. This new syndrome presents muscle CoQ deficiency associated with cerebellar ataxia and cerebellar atrophy as the main neurological signs. Biochemically, the hallmark of CoQ deficiency syndrome is a decreased CoQ concentration in muscle and/or fibroblasts. There is no molecular evidence of the enzyme or gene involved in primary CoQ deficiencies associated with cerebellar ataxia, although recently a family has been reported with mutations at COQ2 gene who present a distinct phenotype. Patients with primary CoQ deficiency may benefit from CoQ supplementation, although the clinical response to this therapy varies even among patients with similar phenotypes. Some present an excellent response to CoQ while others show only a partial improvement of some symptoms and signs. CoQ deficiency is the mitochondrial encephalomyopathy with the best clinical response to CoQ supplementation, highlighting the importance of an early identification of this disorder.

Fluctuation-induced phase transition in a spatially extended model for catalytic CO oxidation

A reaction-diffusion master equation has been introduced in order to model the bistable CO oxidation on single crystal metal surfaces at high pressure where the diffusion length becomes small and local fluctuations are important. Analytical solutions can be found in a reduced one-component nonlinear master equation after applying the Weiss mean-field approximation together with the adiabatic elimination of oxygen. It is shown that the Weiss mean-field approximation predicts a symmetry-breaking bifurcation associated with a phase transition. The corresponding stationary solutions of the nonlinear master equation are supported by Gillespie-type Monte Carlo simulations.

Control of diabetes and cardiovascular risk factors in patients with type 2 diabetes in primary care. The gap between guidelines and reality in Spain

To evaluate the level and factors affecting control of diabetes and cardiovascular risk factors in type 2 diabetes (TYPE 2 DM) patients. Multicentre cross-sectional study: a sample of 430 primary care practices across Spain selected 1907 type 2 diabetic patients. The first five consecutive ambulatory patients with TYPE 2 DM were eligible for the inclusion into the survey. Patients were free of known cardiovascular disease (CVD). Control criteria were defined based on 2002 American Diabetes Association (ADA) clinical practice recommendations. A total of 1907 patients (51% women) aged 63 +/- 9 years. Smoking prevalence was 22.6%, 50.6% had levels of A1c < 7%. Mean blood pressure (BP) was 148 +/- 17/86 +/- 10 mmHg. Only 7.8% have achieved the target of BP < 130/80 mmHg. Among the 1180 patients (65%) treated for hypertension, this target was attained in only 4.4% of patients. A measurement for low-density lipoprotein (LDL) cholesterol was available in 1669 patients (88%). Only 5.9% of patients achieved the target of LDL < 100 mg/dl. Among the 638 patients (41.6%) on drug treatment for dyslipidaemia, this target was attained in only 5.6% of patients. Among type 2 diabetic patients in Spain the prevalence of cardiovascular risk factors is high. Control of glycaemia, smoking, BP and LDL are far from optimal despite the widespread use of guidelines for the management of diabetes and CVD. The application of published recommendations needs to be reinforced.

[Cerebral creatine transporter deficiency: an infradiagnosed neurometabolic disease]

INTRODUCTION

Brain creatine deficiencies are a group of inborn errors of metabolism recently recognized which are caused by arginine: glycine amidinotransferase (AGAT) deficiency, guanidinoacetate metiltransferase (GAMT) deficiency and defects in creatine transporter (CRTR). Although all of them are characterized by a brain creatine deficiency, clinical and biochemical features are different.

CASE REPORTS

We present a retrospective study about four patients of masculine sex affected of creatine transporter defects who were recently diagnosed in our centre. We describe the clinical presentation features, the different tests that we used in the diagnosis process (brain magnetic resonance spectroscopy, biochemical analysis of guanidinoacetate and creatine/creatinine ratio in urine), evolution aspects and the response to treatment. The most significative clinical feature was developmental delay mainly in expressive speech, they also presented epilepsy (three cases), autism (three cases), hypotonia (one case) and microcephalia (one case). Brain magnetic resonance spectroscopy showed a low (three cases) or an absence (one case) of creatine level. To confirm the defect we studied the creatine uptake in fibroblasts and molecular analysis of the SLC6A8/creatine transporter gene. Patients with creatine transporter deficiency are being treated with arginine, because a lack of response to creatine.

CONCLUSION

Cerebral creatine transporter deficiency can present with different neurological symptoms but developmental and language delay and epilepsy are the most significative; diagnosis is easy and there are some therapeutical options.

Niemann–Pick C disease in Spain: Clinical spectrum and development of a disability scale

OBJECTIVES

To describe the clinical evolution of Niemann-Pick C disease to identify possible factors involved in the diagnosis and severity of the disease.

METHODS

A clinical database and a severity scale was created to evaluate 45 patients diagnosed with Niemann-Pick type C in the last 28 years in Spain.

RESULTS

Complete clinical data were obtained from 30 patients, all were confirmed to have mutations in the NPC1 gene. Regarding clinical form, 3 were perinatal, 7 severe infantile, 6 late infantile, 11 juvenile and 3 adult. Biochemical phenotype was classic in 26. Splenomegaly was present in 28 patients (93%) with a wide range of age at detection. The first symptom of neurological disease was clumsiness, followed in 2-4 years by cerebellar signs. Ophthalmoplegia appeared 2-4 years later and became complete 1-2 years after onset. Dysarthria appeared by the time of complete ophthalmoplegia. Diagnosis was made before the onset of neurological signs in patients with the severe infantile form, at the time of onset of cerebellar signs in the late infantile form and complete ophthalmoplegia in late onset forms.

CONCLUSIONS

In our series, splenomegaly is present in 96% of patients, even in late onset forms during the first years of life. Clumsiness in children with otherwise normal motor development precedes the onset of ataxia by 2-4 years in Niemann Pick type C. A disability scale could be useful for monitoring evolution, establishing possible phenotypic correlations and evaluating future therapies.

[Orientation of mental retardation from neurometabolic diseases]

INTRODUCTION AND DEVELOPMENT

Isolated mental retardation is rarely caused by metabolic factors. The application of a standardised protocol offers low diagnostic performance. There is no international agreement about what type of metabolic examination must be applied in patients with unspecific mental retardation. Nevertheless, and although they are infrequent, there are a number of inborn errors of metabolism that can present in this way. Urea cycle disorders, different forms of homocystinuria, creatine transport deficiency, 4-hydroxybutyric aciduria, Sanfilippo disease, adenylosuccinate lyase deficit and certain extraordinarily rare congenital disorders of the glycosylation of proteins are some examples of them. It is important first to consider those for which treatment is available and that could be diagnosed genetically for possible family counselling.

CONCLUSIONS

Rather than applying a standardised study protocol it is essential is to perform a thorough appraisal of the signs and symptoms associated with the mental retardation (psychiatric disorders, autistic traits, predominant compromise of language, signs of cerebellar dysfunction, epilepsy, dysmorphic traits), since in most disorders it is necessary to apply specific analyses, which are not included in conventional metabolic studies and are only available in certain reference centres.

Determination of 5-methyltetrahydrofolate in cerebrospinal fluid of paediatric patients: Reference values for a paediatric population

BACKGROUND

Cerebral folate deficiency (CFD) has been described as a neurological syndrome associated with low 5-methyltetrahydrofolate (5-MTHF) values in cerebrospinal fluid (CSF) with normal folate concentrations in plasma. Our aim was to analyse CSF 5-MTHF concentrations in a paediatric control population and in patients with various neurological disorders.

METHODS

We studied plasma and CSF samples from 63 paediatric controls (age range: 2 days to 18 years, average: 3.8 years) and from 165 patients (age range: 1 day to 22 years, average: 5.0 years) with severe epileptic encephalopathies of unknown origin, movement disorders, Rett syndrome and mitochondrial diseases. CSF 5-methyltetrahydrofolate was analysed by reverse phase HPLC with fluorescence detection (excitation: 295 nm and emission: 355 nm).

RESULT

A negative correlation between 5-MTHF values and age of controls was observed (r=-0.468; p<0.0001) and reference values were therefore stratified into 3 age groups. Regarding patients, 122 out of 165 showed normal CSF 5-MTHF values while 43 showed decreased values ranging from profound to mild deficiencies. Increased CSF total protein values were associated with the presence of low 5-MTHF concentrations (chi(2)=7.796; p=0.005).

CONCLUSIONS

The application of this method has been useful for the establishment of reference values and for diagnosis of CFD in paediatric patients. Furthermore, increased CSF total protein concentrations should be considered as a marker of a possible CFD.

Utilidad del análisis del líquido cefalorraquídeo para el estudio de las deficiencias del metabolismo de neurotransmisores y pterinas y del transporte de glucosa y folato a través de la barrera hematoencefálica

BACKGROUND AND OBJECTIVE

In the last few years, it has been described inborn errors of neurotransmitter and pterin metabolism and defects in folate and glucose transport across blood brain barrier. All these defects are classified as rare diseases and needs cerebrospinal fluid (CSF) sample analysis for diagnosis. Our aim was to evaluate the results of the application of a CSF analysis protocol in a pediatric population from Spain and Portugal presenting with neurological disorders of unknown origin.

PATIENTS AND METHOD

We studied CSF samples from and 283 patients with neurological disorders of unknown origin and 127 controls. Neurotransmitters were analysed by HPLC with electrochemical detection, and pterins and 5-methyltetrahydrofolate were determined by HPLC with fluorescence detection.

RESULTS

We diagnosed 3 patients with tyrosine hidroxylase deficiency, 2 with dopa responsive dystonia, 14 with GTP-ciclohydrolase deficiency, 2 with glucose transport deficiency and 43 with cerebral folate deficiency.

CONCLUSIONS

This study allowed us to diagnose new patients, and more importantly, the establishment in all of them of a pharmacological or nutritional treatment. The most frequent defect found was CSF 5-methyltetrahydrofolate deficiency, which was present in different groups of patients.

Abel inversion applied to a small set of emission data from a microwave plasma

In this work we propose a criterion to apply the Abel inversion in the case of a small set of experimental data to be used in laboratory plasmas. The Nestor-Olsen method, spline interpolation, and Fourier transform Abel inversion have been compared in order to study the influence of statistical noise and the number of sampled data. The application of this criterion permits us to obtain a radial distribution of the plasma parameters (densities and temperatures) from the spectral line profiles emitted by the discharge. The proposed criterion has been tested using the lateral intensities of several lines emitted by a microwave helium plasma column generated at atmospheric pressure.

[Early onset Neurobehçet's disease]

INTRODUCTION

Behçet's disease is difficult to diagnose in infancy due to the absence of early clinicopathological pathognomonic symptoms. There have been reports of patients in whom the onset of the disease occurred during the first months of their lives.

CASE REPORT

We describe here the case of a 12-year-old female from Pakistan whose first symptoms appeared at the age of 6 months in the form of fever and skin lesions. The first neurological symptoms appeared at the age of 5 years in the form of ophthalmoplegia, followed by ataxia and dysmetry. Magnetic resonance imaging of the head was a valuable aid in the study of the vascular alterations. She also presented abdominal pains, arthromyalgia, ulcers in the mouth and severely delayed weight gain. Yet, we were finally guided towards a diagnosis by the appearance of ulcers on the genitals, which do not usually occur until puberty, as well as the findings from the skin biopsy study. The serological study revealed the presence of antigen B08. Establishing therapy with methylprednisolone and later with azathioprine brought about the practically complete remission of the clinical picture.

CONCLUSIONS

Behçet's disease, which has been infrequent in our country up till now, is a condition to be taken into account, especially in young female patients from countries with a high incidence rate of oral and genital ulcers, accompanied by neurological symptoms. Knowledge of this syndrome and performing appropriate complementary studies are essential to be able to reach an early diagnosis and for establishing suitable treatment.

Theoretical analysis of internal fluctuations and bistability in CO oxidation on nanoscale surfaces

The bistable CO oxidation on a nanoscale surface is characterized by a limited number of reacting molecules on the catalytic area. Internal fluctuations due to finite-size effects are studied by the master equation with a Langmuir-Hinshelwood mechanism for CO oxidation. Analytical solutions can be found in a reduced one-component model after the adiabatic elimination of one variable which in our case is the oxygen coverage. It is shown that near the critical point, with decreasing surface area, one cannot distinguish between two macroscopically stable stationary states. This is a consequence of the large fluctuations in the coverage which occur on a fast time scale. Under these conditions, the transition times between the macroscopic states also are no longer separated from the short-time scale of the coverage fluctuations as is the case for large surface areas and far away from the critical point. The corresponding stationary solutions of the probability distribution and the mean first passage times calculated in the reduced model are supported by numerics of the full two-component model.

Cerebrospinal fluid concentrations of folate, biogenic amines and pterins in Rett syndrome: treatment with folinic acid

BACKGROUND

Previous studies in Rett syndrome (RS) patients suggested various abnormalities in biogenic amines, pterins, and folate values in cerebrospinal fluid (CSF). Our aim was to analyse these metabolites in CSF of 16 RS patients (age range: 2 - 23 years). Biogenic amines, pterins, and 5-methyltetrahydrofolate were measured by HPLC with electrochemical and fluorescence detection.

RESULTS

CSF values of 5-methyltetrahydrofolate were decreased in 8 out of 16 RS patients (average: 53.6 nmol/L; range: 19 - 92) when compared with our reference values (average: 74.6 nmol/L; range: 45 - 127). These eight patients had epilepsy, while 4 out of 16 RS patients who did not have epilepsy showed normal CSF 5-methyltetrahydrofolate concentrations. Values of biogenic amines or pterins were decreased in four of the patients with low values of 5-methyltetrahydrofolate. No correlation was observed between CSF values of 5-methyltetrahydrofolate and pterins, biogenic amines, or age. Supplementation with folinic acid was applied in six out of the eight patients with CSF 5-methyltetrahydrofolate deficiency. An improvement was noticed in all cases.

CONCLUSIONS

An important percentage of RS patients showed 5-methyltetrahydrofolate concentrations under the reference values. Therefore, analysis of CSF 5-methyltetrahydrofolate seems advisable in RS, especially in patients with epilepsy and those resistant to antiepileptic drugs.

Identification of 25 new mutations in 40 unrelated Spanish Niemann-Pick type C patients: genotype-phenotype correlations

To better characterize Niemann-Pick type C (NPC) in Spain and improve genetic counselling, molecular analyses were carried out in 40 unrelated Spanish patients. The search identified 70/80 alleles (88%) involving 38 different NPC1 mutations, 26 of which are described for the first time. No patient with NPC2 mutations was identified. The novel NPC1 mutations include 14 amino acid substitutions [R372W (c.1114C>T), P434L (c.1301C>T), C479Y (c.1436G>A), K576R (c.1727G>A), V727F (c.2179G>T), M754K (c.2261T>A), S865L (c.2594C>T), A926T (c.2776G>A), D948H (c.2842G>C), V959E (c.2876T>A), T1036K (c.3107C>A), T1066N (c.3197C>A), N1156I (c.3467A>T) and F1224L (c.3672C>G)], four stop codon [W260X (c.780G>A), S425X (c.1274C>A), C645X (c.1935T>A) and R1059X (c.3175C>T)], two donor splice-site mutations [IVS7+1G>A (g.31432G>A) and IVS21+2insG (g.51871insG)], one in-frame mutation [N961_F966delinsS (c.2882del16bpins1bp)] and five frameshift mutations [V299fsX8 (c.895insT), A558fsX11 (c.1673insG), C778fsX10 (c.2334insT), G993fsX3 (c.2973_78delG) and F1221fsX20 (c.3662delT)]. We also identified three novel changes [V562V (c.1686G>A), A580A (c.1740C>G) and A1187A (c.3561G>T)] in three independent NPC patients and five polymorphisms that have been described previously. The combination of these polymorphisms gave rise to the establishment of different haplotypes. Linkage disequilibrium was detected between mutations C177Y and G993fsX3 and specific haplotypes, suggesting a unique origin for these mutations. In contrast, I1061T mutation showed at least two different origins. The most prevalent mutations in Spanish patients were I1061T, Q775P, C177Y and P1007A (10, 7, 7 and 5% of alleles, respectively). Our data in homozygous patients indicate that the Q775P mutation correlates with a severe infantile neurological form and the C177Y mutation with a late infantile clinical phenotype.