Neil R Friedman

Riley Hospital for Children, Indianapolis, Indiana, United States

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Publications (13)42.97 Total impact

  • Journal of Paediatrics and Child Health 04/2013; 49(4):335-6. · 1.25 Impact Factor
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    ABSTRACT: Mutations in the smooth muscle-specific isoform of α-actin (ACTA2) cause vascular smooth muscle dysfunction leading to aortic aneurysm and moyamoya syndrome. A unique R179H mutation in ACTA2 has been reported to result in widespread smooth muscle dysfunction affecting vascular and extravascular smooth muscles. We report a 7-year-old girl with an ACTA2 R179H mutation manifesting with neonatal seizures due to multifocal infarcts, asymmetric motor deficits, global developmental delay, spasticity, congenital bilateral mydriasis, and a large patent ductus arteriosus. Serial magnetic resonance imaging (MRI) of the brain over 7 years showed diffuse supratentorial white matter abnormalities consistent with a progressive leukoencephalopathy. Magnetic resonance angiography of the cerebral vessels showed stenosis in the terminal portion of the bilateral internal carotid arteries with fusiform dilation of the proximal segment. Neonatal onset of neurologic symptoms in ACTA2 mutations has not been previously reported. R179H mutation in ACTA2 represents the severe end of the disease spectrum.
    Journal of child neurology 06/2012; · 1.59 Impact Factor
  • Journal of child neurology 04/2012; · 1.59 Impact Factor
  • Partha S Ghosh, Neil R Friedman, Debabrata Ghosh
    Clinical Pediatrics 04/2012; 51(8):808-11. · 1.27 Impact Factor
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    ABSTRACT: Mowat-Wilson syndrome is a genetic disorder characterized by a distinct facial appearance, moderate-to-severe mental retardation, microcephaly, agenesis of the corpus callosum, Hirschsprung disease, congenital heart disease, and genital anomalies. Ophthalmological abnormalities have been rarely described in patients with this condition which is caused by mutations in the ZEB2 gene. We report a 9-year-old female with this syndrome who has severe ocular abnormalities including bilateral microphthalmia, cataract, and retinal aplasia.
    Ophthalmic Genetics 04/2012; 33(3):159-60. · 1.07 Impact Factor
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    ABSTRACT: We identified a novel missense mutation, c.424G>C (p.Val142Leu) in PRPS1 in a patient with uric acid overproduction without gout but with developmental delay, hypotonia, hearing loss, and recurrent respiratory infections. The uric acid overproduction accompanying this combination of symptoms suggests that the patient presented with phosphoribosylpyrophosphate (PRPP) synthetase superactivity, but recurrent infections have not been associated with superactivity until now. However, recurrent infections are a prominent feature of patients with Arts syndrome, which is caused by PRPS1 loss-of-function mutations, indicating that the patient reported here has an intermediate phenotype. Molecular modeling predicts that the p.Val142Leu change affects both allosteric sites that are involved in inhibition of PRPS1 and the ATP-binding site, which suggests that this substitution can result both in a gain-of-function and loss-of-function of PRPP synthetase. This finding is in line with the normal PRPP synthetase activity in fibroblasts and the absence of activity in erythrocytes of the present patient. We postulate that the overall effect of the p.Val142Leu change on protein activity is determined by the cell type, being a gain-of-function in proliferating cells and a loss-of-function in postmitotic cells. Our results show that missense mutations in PRPS1 can cause a continuous spectrum of features ranging from progressive non-syndromic postlingual hearing impairment to uric acid overproduction, neuropathy, and recurrent infections depending on the functional sites that are affected.
    American Journal of Medical Genetics Part A 02/2012; 158A(2):455-60. · 2.30 Impact Factor
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    ABSTRACT: Hirayama disease has been mainly reported from Asia; only a few cases are from the Western hemisphere, particularly North America. This is a retrospective chart review of patients < 18 years, diagnosed with Hirayama disease from a single center over 10 years. We diagnosed 6 children (4 boys), 15.1 ± 1.2 years of age. Symptom onset was 3 months to 3 years before presentation. All had unilateral or bilateral asymmetric distal upper extremity weakness without objective sensory loss. Oblique amyotrophy and cold paresis were noted in 5. On electromyography, acute-on-chronic denervation was most frequently noted in cervical-8 (C8) and thoracic-1 (T1) myotomes followed by cervical-7 (C7) myotome in both upper limbs, sparing C5-C6 myotomes. Cervical magnetic resonance imaging (MRI) was abnormal in 3. Symptoms progressed over a mean of 16.5 months. Treatment consisted of placement of cervical collar. Heightened awareness of this entity among pediatric neurologists in North America will lead to early diagnosis and intervention, avoiding unnecessary investigations.
    Journal of child neurology 12/2011; 26(12):1542-7. · 1.59 Impact Factor
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    ABSTRACT: Reversible cerebral vasoconstriction syndrome is characterized by a reversible segmental and multifocal vasoconstriction of cerebral arteries, and severe headaches with or without focal neurologic deficits or seizures. A 15-year-old boy presented with thunderclap headache. He had severe hypertension, although his neurologic examination was normal. Initial workup for thunderclap headache to exclude subarachnoid or intracranial hemorrhage, meningitis, pituitary apoplexy, or venous sinus thrombosis was negative. Brain magnetic resonance angiography and cerebral angiography demonstrated bilateral anterior and posterior circulation diffuse, multifocal, vascular irregularities (beading and stenosis) suggestive of underlying vasculopathy or vasculitis. He was started on verapamil. There was complete reversal of the vascular abnormalities in 6 weeks evident by magnetic resonance angiography, with resolution of headache and normalization of blood pressure. Reversible cerebral vasoconstriction syndrome has been rarely reported in children. This case report highlights the diagnostic dilemma and management of the rare childhood presentation of this condition.
    Journal of child neurology 07/2011; 26(12):1580-4. · 1.59 Impact Factor
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    ABSTRACT: A 17-year-old girl presented with migraine with prolonged aura and aura without headache. Neurologic examination was normal. Her mother, who did not have a history of migraine, developed right-face and -arm numbness at the age of 45. Evaluation revealed white matter changes consistent with CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), and genetic testing showed a Notch3 gene mutation consistent with CADASIL. Our patient's MRI revealed white matter changes and the same Notch3 gene mutation. Low-dose aspirin was started in an attempt to prevent stroke. CADASIL is considered a degenerative disease of adult onset that leads to progressive neurologic deterioration. Onset of symptoms is in the third decade. Migraine, one of its most common manifestations, can develop in childhood. Evaluation for secondary causes is warranted in select pediatric patients who present with atypical migraine, when there is a family history of CADASIL or atypical patterns such as aura without headache, or in the presence of white matter abnormalities. The pathophysiology of CADASIL is poorly understood, and there is no proven effective therapy. Patients require genetic counseling and close follow-up. It is not known if interventions such as antiplatelet therapy are beneficial if instituted early in the course of the disease. Screening of family members at risk for CADASIL, even in the pediatric population, should be considered and offered to patients with CADASIL and their families. CADASIL has rarely been described in the pediatric population. This case report expands our current understanding of the disorder in children.
    PEDIATRICS 11/2010; 126(6):e1603-7. · 4.47 Impact Factor
  • Neil R Friedman
    The Lancet Neurology 10/2010; 9(11):1042-4. · 23.92 Impact Factor
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    ABSTRACT: Creatinine as a marker of renal function has limited value in Duchenne muscular dystrophy (DMD) because of reduced muscle mass. Alternative methods of assessing renal function are sorely needed. Cystatin C, a nonglycosylated protein unaffected by muscle mass, is potentially an ideal biomarker of nephrotoxicity for this population but requires validation. In all, 75 subjects were recruited: 35 DMD (mean age 10.8 +/- 5.4 years, corticosteroids n = 19, ambulatory n = 26), 29 healthy controls, 10 with renal disease, and one DMD with renal failure. Cystatin C levels in DMD were normal irrespective of age, ambulation, or corticosteroid treatment. Serum cystatin C was 0.67 +/- 0.11 mg/l compared to normal controls 0.69 +/- 0.09. mg/l. In these same individuals serum creatinine was severely reduced (0.27 +/- 0.12 mg/dl) versus normals (0.75 +/- 0.15 mg/dl, P < 0.01). In one DMD subject in renal failure, cystatin C was elevated. This study demonstrates the potential value of cystatin C as a biomarker for monitoring renal function in DMD. Its applicability extends to other neuromuscular diseases.
    Muscle & Nerve 08/2009; 40(3):438-42. · 2.31 Impact Factor
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    Neil Friedman
    Advances in Pediatrics 01/2009; 56:271-99.
  • Neil R. Friedman, Manikum Moodley