Neurological development and iron supplementation in healthy late-preterm neonates: a randomized double-blind controlled trial.

Late-preterm infants (LPT) are at increased risk for long-term neurodevelopmental sequelae and iron deficiency. The aim of the study is to assess the positive effect of iron supplementation on psychomotor development in healthy LPT. We designed a randomized placebo-controlled double-blind trial dividing the newborns into two groups. Every patient was assessed using the Griffiths Mental Development Scales (GMDS)-II edition at 12-month post-conceptional age. The study was performed at the Neonatology Unit of our Hospital, in Italy. Sixty-six healthy LPT infants born between 340/7 and 366/7 weeks of gestational age were enrolled in the study. One group received martial prophylaxis from the third week of life to 6 months of post-conceptional age (2 mg/kg/day of iron pidolate), the other received placebo. Fifty-two of the enrolled infants were assessed using the GMDS at 12-month of post-conceptional age. Statistical analysis of the mean scores of the Griffiths subscales was performed. There was a difference in the mean developmental quotient (DQ) (p < 0.01) between the two groups: iron group mean DQ 121.45 ± 10.53 vs placebo group mean DQ 113.25 ± 9.70. Moreover, mean scores of the Griffiths subscales A, B, and D showed significant differences between the two groups (scale A p < 0.05, scale B p < 0.02, scale D p < 0.01, respectively).Conclusions: We recommend that all LPT neonates receive iron supplementation during the first 6 months of life in order to improve their 1-year neurodevelopmental quotient. What is Known: • Late-preterm infants (LPT) are at increased risk for long-term neurodevelopmental sequelae and also for iron deficiency. • Iron deficiency is an independent risk factor for adverse neurological outcomes. What is New: • Healthy late-preterm who received iron supplementation during the first 6 months of life achieved better neurological outcomes at 12-month post-conceptional age than LPT who received placebo. • Our study strongly supports the need for the implementation of martial prophylaxis in LPT neonates.

Sometimes they come back: New and old spinal muscular atrophy adults in the era of nusinersen.

BACKGROUND AND PURPOSE: Following the commercial availability of nusinersen, there have been a number of new referrals of adults with spinal muscular atrophy (SMA) not regularly followed in tertiary-care centers or enrolled in any disease registry. METHODS: We compared demographics and disease characteristics, including assessment of motor and respiratory function, in regularly followed patients and newcomers subdivided according to the SMA type. RESULTS: The cohort included 166 adult patients (mean age: 37.09 years): one type I, 65 type II, 99 type III, and one type IV. Of these 166, there were 67 newcomers. There was no significant difference between newcomers and regularly followed patients in relation to age and disease duration. The Hammersmith Functional Motor Scale Expanded and Revised Upper Limb Module scores were higher in the regularly followed patients compared to newcomers in the whole cohort and in both SMA II and II. A difference was also found on ventilatory status (p = 0.013) and Cobb's angle >50° (p = 0.039) between the two subgroups. No difference was found in scoliosis surgery prevalence (p > 0.05). CONCLUSIONS: Our results showed differences between the two subgroups, even if less marked in the type III patients. In the type II patients, there was a higher proportion of newcomers who were in the severe end of the spectrum. Of the newcomers, only approximately a third initiated treatment, as opposed to the 51% in the regularly followed patients. The identification of patients who were not part of the registries will help to redefine the overall prevalence of SMA and the occurrence of different phenotypes.

Brain morphometry of preschool age children affected by autism spectrum disorder: Correlation with clinical findings.

The aim of our study was to use a combined imaging and clinical approach to identify possible patterns of clinical and imaging findings in a cohort of preschool age autism spectrum disorder (ASD) patients. In order to identify imaging patterns that could be related to specific clinical features, a selected group of ASD patients (age range 3-6 years) without dysmorphic features, epilepsy or other major neurological signs, malformations or other lesions at MRI was subjected to brain volumetric analysis using semiautomatic brain segmentation. An age-matched group of typically developing children was subjected to the same analysis. Our results were consistent with previous literature: Total gray matter volume, total cortical gray matter volume and amygdalar volumes were significantly greater in the ASD group than the control group. When we divided the study group into subgroups on the basis of clinical findings such as high- or low-functioning, or verbal and nonverbal, the only significant difference between verbal and nonverbal subjects was in cerebellar hemispheric size. In conclusions, our results confirm that newer brain MRI techniques using semiautomatic brain segmentation can provide information useful for defining the differences between ASD patients and controls, particularly if they form part of an integrated approach between MRI and cognitive-behavioral and genetic data. Clin. Anat. 32:143-150, 2019. © 2018 Wiley Periodicals, Inc. HIGHLIGHTS: Combined imaging and clinical approach in autism spectrum disorders Semiautomatic brain segmentation in a selected preschool age ASD group Reduced total cerebellar white matter volume in non-verbal ASD patients.

Therapeutic approaches for spinal muscular atrophy (SMA).

Spinal muscular atrophy is an autosomal recessive neurodegenerative disorder characterized by progressive muscle wasting and loss of muscle function due to severe motor neuron dysfunction, secondary to mutations in the survival motor neuron 1 (SMN1) gene. A second neighboring centromeric gene, SMN2, is intact in all patients but contains a C-to-T variation in exon 7 that affects a splice enhancer and determines exclusion of exon 7 in the majority of its transcript, leading to an unstable protein that cannot substitute for mutant SMN1. Following successful studies on disease models and intensive studies on SMN functions in the past decade, SMN upregulation targeting SMN2, has been suggested as a possible therapeutic approach. Recently, we have witnessed an historical turning point with the first disease-modifying treatment receiving Food and Drug Administration approval and now being available to patients also outside the clinical trial. This innovative treatment is an antisense oligonucleotide, which, administered intrathecally, is able to increase exon 7 inclusion in the majority of the SMN2 mRNA and increase the production of fully functional SMN protein. Alternative advanced therapies, such as viral vector mediated gene therapy and orally available small molecules, are also showing promising results in early clinical trial phases.

Development of a patient-reported outcome measure for upper limb function in Duchenne muscular dystrophy: DMD Upper Limb PROM.

AIM: To develop a patient-reported outcome measure (PROM) assessing upper limb function related to activities of daily living (ADL) that cannot be observed in a clinical setting, specifically for patients with Duchenne muscular dystrophy (DMD) across a wide age range, applicable in the different stages of the disease. METHOD: The developmental process was based on US Food and Drug Administration guidelines. This included item generation from a systematic review of existing tools and expert opinion on task difficulty and relevance, involving individuals with DMD. Cultural aspects affecting ADL were taken into consideration to make this tool applicable to the broad DMD community. Items were selected in relation to a conceptual framework reflecting disease progression covering the full range of upper limb function across different ADL domains. RESULTS: After pilot testing and iterative Rasch analyses, redundant or clinically irrelevant items were removed. The final questionnaire consists of 32 items covering four domains of ADL (food, self-care, household and environment, leisure and communication). Test-retest reliability was excellent. INTERPRETATION: A DMD-specific upper limb PROM was developed on the basis of clinical relevance and psychometric robustness. Its main purpose is to document the patient self-reported natural history of DMD and assess the efficacy of interventions.

Safety, tolerability and pharmacokinetics of eteplirsen in young boys aged 6-48 months with Duchenne muscular dystrophy amenable to exon 51 skipping.

Eteplirsen is FDA-approved for the treatment of Duchenne muscular dystrophy (DMD) in exon 51 skip-amenable patients. Previous studies in boys > 4 years of age indicate eteplirsen is well tolerated and attenuates pulmonary and ambulatory decline compared with matched natural history cohorts. Here the safety, tolerability and pharmacokinetics of eteplirsen in boys aged 6-48 months is evaluated. In this open-label, multicenter, dose-escalation study (NCT03218995), boys with a confirmed mutation of the DMD gene amenable to exon 51 skipping (Cohort 1: aged 24-48 months, n = 9; Cohort 2: aged 6 to < 24 months, n = 6) received ascending doses (2, 4, 10, 20, 30 mg/kg) of once-weekly eteplirsen intravenously over 10 weeks, continuing at 30 mg/kg up to 96 weeks. Endpoints included safety (primary) and pharmacokinetics (secondary). All 15 participants completed the study. Eteplirsen was well tolerated with no treatment-related discontinuations, deaths or evidence of kidney toxicity. Most treatment-emergent adverse events were mild; most common were pyrexia, cough, nasopharyngitis, vomiting, and diarrhea. Eteplirsen pharmacokinetics were consistent between both cohorts and with previous clinical experience in boys with DMD > 4 years of age. These data support the safety and tolerability of eteplirsen at the approved 30-mg/kg dose in boys as young as 6 months old.

Longitudinal data of neuropsychological profile in a cohort of Duchenne muscular dystrophy boys without cognitive impairment.

The aim of the study was to re-assess neuropsychological profile in a group of boys with Duchenne muscular dystrophy without intellectual disability and neuropsychiatric disorder three years apart from a previous evaluation, to establish possible changes over time. We were also interested in defining more in detail correlation between genotype and neuropsychological phenotype. Thirty-three of the previous 40 subjects (mean age at follow up: 10 years and 7 months) agreed to participate in the follow up study and to perform the new assessment. The results confirm a typical neuropsychological profile, with difficulty in the manipulation of stored information, poor abstract reasoning and planning capacity and impulsiveness, supporting the involvement of a cerebellar striatal cortical network for these children. The more detailed description of subgroups of subjects, according to the real expression of Dp140, let to reveal possible genotype-neuropsychological phenotype correlations, and a more general neuropsychological impairment emerged in boys without Dp140 expression.

Enhanced human brain associative plasticity in Costello syndrome.

Costello syndrome (CS) is a rare multiple congenital anomaly disorder which is caused by germline mutations in the v-Ha-ras Harvey rat sarcoma viral oncogene homologue (HRAS) proto-oncogene. Experimental data suggest perturbing effects of the mutated protein on the functional and structural organization of networks of cerebral cortex and on the activity-dependent strengthening of synaptic transmission known as long term potentiation (LTP). In five patients with molecularly proven diagnosis of CS and in a group of 13 age-matched control subjects we investigated activity-dependent synaptic plasticity. To this end, we used a paired associative stimulation (PAS) protocol, in which left ulnar nerve stimuli were followed by transcranial magnetic stimulation (TMS) pulses to right cortical hand area, and recorded motor evoked potentials (MEPs) by single pulse TMS from left first dorsal interosseus (FDI) muscle before and after PAS. In 4 out of 5 CS patients and in a subgroup of nine control subjects we also evaluated the time course and the topographical specificity of PAS after-effects. In these two subgroups, MEPs were measured before, immediately after and 30 min after PAS in the left FDI and left abductor pollicis brevis (APB). While the PAS protocol led to a 65% increase of the FDI MEP amplitude in controls, the LTP-like phenomenon was significantly more pronounced in CS patients, with motor responses increased by 230%. In addition, CS patients showed a similar MEP increase in both muscles while control subjects showed a slight increase in APB and only immediately after PAS. We hypothesize that the extremely enhanced PAS after-effects could be due to the influence of HRAS activity on the susceptibility of synapses to undergo LTP.

Cranial ultrasound evaluation in term neonates.

BACKGROUND: Term neonates (TN) are not routinely submitted to cranial ultrasound scan (CUS), since they are not considered at high risk for developing cerebral lesions. AIMS: To investigate the prevalence of cerebral abnormal findings in term neonates (TN), to identify the associated clinical features and to better target neonatal CUS investigations. STUDY DESIGN: Prospective observational study. SUBJECTS: A total number of 1805 healthy TN underwent CUS. 1181 neonates had clinical features supposed to increase the risk for cerebral abnormal findings (study cohort), 624 were controls. OUTCOME MEASURES: Prevalence of minimal, minor, and major cerebral abnormal findings was analyzed in six different categories of low-risk TN and compared to controls. RESULTS: Variations from normality at the neonatal CUS were observed in 402 TN (22.27%). In half of the cases the ultrasound findings were minimal abnormal findings, while minor abnormal findings were found in 179 TN (9.92%). About 1% of the studied neonates showed major cerebral abnormal findings potentially compromising neurodevelopmental outcome. The prevalence of the observed abnormal findings varied significantly in the different low-risk categories. CONCLUSIONS: The clinical features significantly increasing the risk for cerebral anomalies in healthy TN were microcrania, macrocrania, mild neurologic signs, and the detection of mild variations from normal cerebral aspect at the antenatal ultrasound evaluation.

A bone remodeling model governed by cellular micromechanics and physiologically based pharmacokinetics.

This study describes a mathematical model for bone remodeling that integrates the bone cells activities with the pharmacological dynamics for bone-seeking agents. The evolution of bone cells population involves the osteoblast-osteoclast signaling mediated by biochemical factors and receives both mechanical stimulus evaluated at the microscale and pharmacological regulation. A physiologically based pharmacokinetic model (PBPK) for bone-seeking agents was developed to provide the drug concentration on bone sites and feed the remodeling algorithm. The drug effect on bone was reproduced coupling three different strategies: modification of the RANKL expression, increase the osteoclast apoptosis and change in the rate of differentiation of preosteoblasts. Computational simulations were performed in the PBPK model considering different dosing regimens. A 3D finite element model of a proximal femur was generated and the simulation of the bone remodeling algorithm were implemented in Matlab. The results indicate that the proposed integrated model is able to capture adequately the expected adaptive behavior of bone subjected to mechanical and pharmacological stimulus. The model demonstrated to have potential for use as a platform to investigate therapies and may help in the study of new drugs for bone diseases.

Duchenne muscular dystrophy: preliminary experience with sacubitril-valsartan in patients with asymptomatic left ventricular dysfunction.

OBJECTIVE: Duchenne muscular dystrophy (DMD) is an inherited X-linked recessive neuromuscular disease caused by mutations of the dystrophin gene, leading to early and progressive muscle deterioration and dilated cardiomyopathy. The aim of this investigation was to assess whether treatment with sacubitril/valsartan (S/V) is well tolerated and may have beneficial effects in DMD patients with left ventricle (LV) dysfunction. PATIENTS AND METHODS: We administered S/V to 3 DMD patients (19-29 yeard old) with LV ejection fraction <35% at echocardiography but no symptoms of heart failure. All patients were on optimal medical therapy. S/V was initiated at a very low dose of 12/13 mg/die, after withdrawal of angiotensin-converting enzyme inhibitor therapy, and slowly titrated to the dose of 49/51 mg twice daily or the maximally tolerated dose. Clinical and echocardiographic follow-up was performed after 3, 6 and 12 months. RESULTS: At baseline, the LV ejection fraction was 32±1%. A significant improvement of LV ejection fraction was observed at 3 months (44.0±6.0%; p<0.05), which was maintained at 6 (45.7±5.0%) and 12 (43.3±3.2%) months (p<0.05 for both). No relevant side effects were reported throughout the period of the study. CONCLUSIONS: Our preliminary data suggest that, in DMD patients with reduced LV ejection fraction, S/V is safe and may improve LV function.

Measuring Outcomes in Adults with Spinal Muscular Atrophy - Challenges and Future Directions - Meeting Report.

Spinal muscular atrophy (SMA) is a progressive autosomal recessive motor neuron disease which affects 1 in 6,000-10,000 live births, caused by loss of the survival motor neuron 1 gene (SMN1). A major focus of therapeutic developments has been on increasing the full-length SMN protein by increasing the inclusion of exon 7 in SMN2 transcripts, enhancing SMN2 gene expression, stabilizing the SMN protein or replacing the SMN1 gene.In June 2017, FDA and EMA have approved the antisense oligonucleotide Nusinersen as the first treatment for all SMA subtypes without age restriction. While prominent treatment effects have been observed in the earlier stages of the disease and in patients up to 15 years of age, there is only limited data from clinical trials in adult SMA patients. First real-world data from neuromuscular clinical centers suggest a therapeutic benefit of nusinersen with a favourable safety profile also in adult SMA patients: in several cases, relevant improvements of motor function is achieved, which might lead to enhanced autonomy in daily life activities and improved quality of life. Systematic follow-up of the motor status with validated instruments is crucial for an adequate monitoring of the therapeutic effects but most of the widely used scales and scores have been developed and evaluated for the pediatric population only. International neuromuscular experts have met in Frankfurt/Main, Germany in May 2019 to discuss relevant aspects of the diagnostic pathway and patient management in adult SMA. The recommendations and challenges in this patient population are discussed.

Transcriptional behavior of DMD gene duplications in DMD/BMD males.

DMD gene exons duplications account for up to 5-10 % of Duchenne (DMD) and up to 5-19% of Becker (BMD) muscular dystrophies; as for the more common deletions, the genotype-phenotype correlation and the genetic prognosis are generally based on the "reading frame rule". Nevertheless, the transcriptional profile of duplications, abridging the genomic configuration to the eventual protein effect, has been poorly studied. We describe 26 DMD gene duplications occurring in 33 unrelated patients and detected among a cohort of 194 mutation-positive DMD/BMD patients. We have characterized at the RNA level 16 of them. Four duplications (15%) behave as exception to the reading frame rule. In three BMD cases with out-of-frame mutations, the RNA analysis revealed that exon skipping events occurring in the duplicated region represent the mechanism leading to the frame re-establishment and to the milder phenotype. Differently, in a DMD patient carrying an in-frame duplication the RNA behaviour failed to explain the clinical phenotype which is probably related to post-transcriptional-translational mechanisms. We conclude that defining the RNA profile in DMD gene duplications is mandatory both for establishing the genetic prognosis and for approaching therapeutic trials based on hnRNA modulation.

Early development of epileptic infants with pre- or perinatal brain injuries: role of the epileptic disorder.

To try to understand the causative role of epilepsy PER SE in the developmental deterioration of brain injured infants, twenty-eight infants affected with early acquired, pre- and perinatal brain injuries were enrolled and divided into three groups, a) those with West syndrome, b) those with other non-West epilepsies, and c) those without epilepsy. Developmental monitoring consisted of a full clinical assessment, including examination of visual function, Griffiths developmental scales, standard EEG, long-term monitoring when necessary, and MRI, from the seizure onset or the first observation to the end of follow-up. Patients with epilepsy showed at study onset abnormal clinical features (neurological and developmental) distinct from those of non-epileptic patients, partially due to the varying severity of their brain injuries. A definite differentiation between groups was observed in the clinical evolution that showed among the epileptic patients, mostly in West syndrome, a significant deterioration. Moreover, impaired visual function at seizure onset was possibly associated with a bad developmental evolution. A developmental deterioration, mostly in West syndrome, accounts for a causative role of the epileptic disorder PER SE, but in few cases it was also observed in infants with only a brain injury, suggesting other aetiopathogenic mechanisms. The predictive value of early visual function seems to be confirmed.

POMT1 and POMT2 mutations in CMD patients: a multicentric Italian study.

Mutations in POMT1 and POMT2 genes were originally identified in Walker-Warburg syndrome (WWS) and subsequently reported in patients with milder phenotypes characterised by mental retardation with or without brain abnormalities and without ocular malformations. As part of a multicentric Italian study we screened the POMT1 and POMT2 genes in 61 congenital muscular dystrophy (CMD) patients with alpha-dystroglycan reduction on muscle biopsy and/or clinical and radiological findings suggestive of the known forms of CMD with alpha-dystroglycan deficiency. The aim of the study was to establish how frequently mutations in POMT1 and POMT2 occur in CMD patients in the Italian population and to evaluate the spectrum of associated phenotypes. Thirteen patients showed mutations in POMT1 and five harboured mutations in POMT2, accounting for a total of 20 different mutations, eight of which were novel (two in POMT1 and six in POMT2). Normal brain MRI associated with mental retardation and microcephaly was the most frequent finding in patients with mutations in POMT1 (six out of 13), but was also found in a patient with POMT2 mutations. Predominant cerebellar hypoplasia was also frequent both in patients with POMT1 (three out of 13) and POMT2 (three out of 5) mutations. A MEB phenotype with frontal cortical dysplasia and pons abnormalities was found in two patients with POMT1 and in one with POMT2 mutations, while a WWS phenotype was only found in a case with mutations in POMT1. Mutations causing frameshifts and stop codons were responsible for the more severe phenotypes. Our results provide further evidence that, as previously reported for FKRP, the array of mutations in POMT1 and POMT2 is ample and the spectrum of associated phenotypes is wider than initially thought.

Swallowing difficulties in Duchenne muscular dystrophy: indications for feeding assessment and outcome of videofluroscopic swallow studies.

Feeding difficulties are known to occur with advancing age in Duchenne muscular dystrophy (DMD). We evaluated the role of videofluoroscopy swallow study (VFSS) in a group of 30 DMD patients with feeding difficulties. Indications for feeding assessment were: respiratory infections potentially attributable to aspiration (n=10) and/or episodes of choking (n=24) subdivided into isolated choking events (n=8) and regular choking during swallowing (n=16). Indications for assessment were analysed in relation to the VFSS results. Median age at assessment was 17.13 years (range 6-31.4). Twenty-four VFSS were performed. Prolonged chewing and effortful bolus transport for solids increased with age. Swallow trigger was normal in the majority of cases. All patients had some post-swallow pharyngeal residue around the laryngeal inlet increasing in volume with age. Although this residue did not result in aspiration, it was worse in patients that were frequently choking. Three patients intermittently had penetration of the supraglottic space that did not reach the vocal folds during the swallow. Our results suggest that reported swallowing problems when assessed are not always associated with difficulties on VFSS. It is the oral phase of swallowing that is most significantly affected in DMD. The pharyngeal phase is well triggered but is weak with incomplete pharyngeal clearance leaving pharyngeal residue. Insufficient or effortful chewing coupled with weak clearance may predispose them to choking episodes either as a one off event or with increasing frequency with age. This study suggests that VFSS may not be of additional benefit to careful feeding history and observation in DMD with feeding difficulties.

Visual function in Noonan and LEOPARD syndrome.

The aim of the study was to assess various aspects of visual and visuoperceptual function in patients with Noonan syndrome (NS) or LEOPARD syndrome (LS) with mutations affecting the PTPN11, SOS1 and RAF1 genes. Twenty-four patients were assessed with a battery of tests assessing visual function including ophthalmological and orthoptic evaluation and age appropriate behavioural visual tests, including measures of crowding acuity (Cambridge crowding cards), and stereopsis (TNO test). Twenty-one subjects were also assessed with the visuo-motor integration (VMI) test. Twenty of the 24 patients (83%) had abnormalities of visual function on at least one of the tests used to assess visual function or on ophthalmological examination, and 7 of 21 (33%) also had abnormalities on VMI. Ocular movements and stereopsis were most frequently abnormal (50% and 79%, respectively). Our results suggest that visual and visuoperceptual abilities are commonly impaired in patients with Noonan and LEOPARD syndrome and they are probably related to a multifactorial etiology.

Cognitive profile in Duchenne muscular dystrophy boys without intellectual disability: The role of executive functions.

The aim of our prospective observational study was to assess profiles of cognitive function and a possible impairment of executive functions in a cohort of boys with Duchenne muscular dystrophy without intellectual and behavior disability. Forty Duchenne boys (range of age: 6 years to 11 years and 6 months) were assessed by Wechsler Intelligence scale and battery of tests including tasks assessing working memory and executive functions (inhibition and switching, problem solving and planning). In our cohort some aspects of cognitive function were often impaired. These included multitasking, problem solving, inhibition and working memory necessary to plan and direct goal oriented behavior. Our results support the suggestion that aspects of cognitive function could be impaired even in boys without intellectual disability and support the hypothesis that executive functions may play an important role in specific aspects of cognitive impairment in Duchenne muscular dystrophy.

A congenital myopathy with diaphragmatic weakness not linked to the SMARD1 locus.

Severe diaphragmatic weakness in infancy is rare. Common causes include structural myopathies, neuromuscular transmission defects, or anterior horn cell dysfunction (spinal muscular atrophy with respiratory distress, SMARD1). We describe a form of infantile diaphragmatic weakness without mutations in the SMARD1 gene, in which pathological and clinical features differ from known conditions, and investigations suggest a myopathy. We identified seven cases in four families. All presented soon after birth with feeding and breathing difficulties, marked head lag, facial weakness, and preserved antigravity movements in the limbs, with arms weaker than legs. All had paradoxical breathing and paralysis of at least one hemi-diaphragm. All required gastrostomy feeding, and all became ventilator-dependent. Investigations included myopathic EMG, muscle biopsy showing myopathic changes, normal electrophysiology and no mutations in SMN1 or IGHMBP2. These seven infants are affected by a myopathic condition clinically resembling SMARD1. However, its pathogenesis appears to be a myopathy affecting predominantly the diaphragm.

The Hammersmith functional score correlates with the SMN2 copy number: a multicentric study.

Previous studies showed that SMN2 copy number correlates inversely with the disease severity. Our aim was to evaluate SMN2 copy numbers and the Hammersmith functional motor scale in 87 patients with SMA II in order to establish whether, within SMAII, the number of copies correlates with the severity of functional impairment. Our results showed a relative variability of functional scores, but a significant correlation between the number of SMN2 genes and the level of function.