Joubert syndrome: a model for untangling recessive disorders with extreme genetic heterogeneity

BACKGROUND

Joubert syndrome (JS) is a recessive neurodevelopmental disorder characterised by hypotonia, ataxia, cognitive impairment, abnormal eye movements, respiratory control disturbances and a distinctive mid-hindbrain malformation. JS demonstrates substantial phenotypic variability and genetic heterogeneity. This study provides a comprehensive view of the current genetic basis, phenotypic range and gene-phenotype associations in JS.

METHODS

We sequenced 27 JS-associated genes in 440 affected individuals (375 families) from a cohort of 532 individuals (440 families) with JS, using molecular inversion probe-based targeted capture and next-generation sequencing. Variant pathogenicity was defined using the Combined Annotation Dependent Depletion algorithm with an optimised score cut-off.

RESULTS

We identified presumed causal variants in 62% of pedigrees, including the first B9D2 mutations associated with JS. 253 different mutations in 23 genes highlight the extreme genetic heterogeneity of JS. Phenotypic analysis revealed that only 34% of individuals have a 'pure JS' phenotype. Retinal disease is present in 30% of individuals, renal disease in 25%, coloboma in 17%, polydactyly in 15%, liver fibrosis in 14% and encephalocele in 8%. Loss of CEP290 function is associated with retinal dystrophy, while loss of TMEM67 function is associated with liver fibrosis and coloboma, but we observe no clear-cut distinction between JS subtypes.

CONCLUSIONS

This work illustrates how combining advanced sequencing techniques with phenotypic data addresses extreme genetic heterogeneity to provide diagnostic and carrier testing, guide medical monitoring for progressive complications, facilitate interpretation of genome-wide sequencing results in individuals with a variety of phenotypes and enable gene-specific treatments in the future.

L-2-hydroxyglutaric aciduria: identification of ten novel mutations in the L2HGDH gene

L-2-hydroxyglutaric aciduria (L-2-HGA) is a metabolic disease with an autosomal recessive mode of inheritance. It was first reported in 1980. Patients with this disease have mutations in both alleles of the L2HDGH gene. The clinical presentation of individuals with L-2-HGA is somewhat variable, but affected individuals typically suffer from progressive neurodegeneration. Analysis of urinary organic acids reveals an increased signal of 2-hydroxyglutaric acid, mainly as the L-enantiomer. L-2-HGA is known to occur in individuals of various ethnic backgrounds, but up to now mutation analysis has been mainly focused on patients of Turkish and Portuguese origin. This led us to confirm the diagnosis on the DNA level and undertake the corresponding mutation analysis in individuals of diverse ethnicity previously diagnosed with L-2-HGA on the basis of urinary metabolites and clinical/neuroimaging data. In 24 individuals from 17 families with diverse ethnic and geographic origins, 13 different mutations were found, 10 of which have not been reported previously. At least eight of the patients were compound heterozygotes. The identification of two mutations (c.751C > T and c.905C > T in exon 7) in patients with different origins supports the view that they occurred independently in different families. In contrast, the mutation c.788C > T was detected in all six Venezuelan patients originating from the same Caribbean island of Margarita, but not in other patients, thus rendering a founder effect likely. None of the mutations was found in the control population, indicating that they are most probably causative. Mutation analysis may improve the quality of diagnosis and prenatal diagnosis of L-2-HGA.

Life-threatening neurological complications after bone marrow transplantation in children

Neurological complications may occur in BMT recipients (11-59%), frequently contributing to morbidity or mortality. They are the main causes of death in 10-15%. Life-threatening neurological complications were seen in 11 out of 113 (9.7%) children who underwent BMT from HLA-matched family (n=7) or mismatched donors (n=4) at our institution. Diagnoses of patients with neurological complications were acute myeloblastic leukemia (AML) (five), thalassemia major (two), Fanconi anemia (two), Omenn syndrome (one) and leukodystrophy (one), and the neurological events were seen between days +13 and +85 after transplantation. Minor symptoms including reversible, nonrepetitive seizures were excluded. Cyclosporine A toxicity was diagnosed in six children. The rest of the complications were brain abscess/meningoencephalitis (two), severe hypomagnesemia (one), busulfan toxicity (one), sustained hypertension (three), and intracranial hemorrhage (three). Six patients with neurological complications suffered from >grade II graft-versus-host disease (GvHD), and all were high risk for transplant-related complications. In this study, risk status of the underlying disease, mismatched transplantation, a diagnosis of AML (advanced stage), older age and >grade II GvHD were important adverse factors for the development of severe life-threatening neurological complications.

Autosomal recessive form of periventricular heterotopia

BACKGROUND

Familial periventricular heterotopia (PH) represents a disorder of neuronal migration resulting in multiple gray matter nodules along the lateral ventricular walls. Prior studies have shown that mutations in the filamin A (FLNA) gene can cause PH through an X-linked dominant inheritance pattern.

OBJECTIVE

To classify cortical malformation syndromes associated with PH.

METHODS

Analyses using microsatellite markers directed toward genomic regions of FLNA and to a highly homologous autosomal gene, FLNB, were performed on two pedigrees to evaluate for linkage with either filamin gene.

RESULTS

Two consanguineous pedigrees with PH that suggest an autosomal recessive inheritance pattern are reported. MRI of the brain revealed periventricular nodules of cerebral gray matter intensity, typical for PH. Seizures or developmental delay appeared to be a common presenting feature. Microsatellite analysis suggested no linkage to FLNA or FLNB.

CONCLUSIONS

Autosomal recessive PH is another syndromic migrational disorder, distinct from X-linked dominant PH. Further classification of these different syndromes will provide an approach for genetic evaluation.

Mental retardation with rare fragile site expressed at 2q11

Several rare autosomal folate sensitive fragile sites were reported in individuals with mental retardation, neurological abnormalities, and multiple congenital malformations. Only three of them: fra(11)(q22.3), fra(X)(q27.3) and fra(X)(q28), are known to be associated with mental retardation and phenotypic abnormalities. A possible association of the other rare fragile sites with idiopathic mental retardation is still being discussed. Here, a girl who has a fragile site at 2q11 with minor congenital anomalies and mental retardation is presented. This case has recalled the question of idiopathic mental retardation that might be the clinical expression of rare FSFS. Fragility was observed at 2q11 with a frequency of 3% in her cells along with a partial endoreduplication at 2 q11-->qter.

A case of leukoencephalopathy with vanishing white matter

A 6-year old Turkish boy with a recently defined entity: "leukoencephalopathy with vanishing white matter" is described. He was born to consanguinous parents. His psychomotor development was normal till he first presented with fever and generalized tonic-clonic seizures at the age of 2.5, followed by rapid motor and mental deterioration. Decerebrate posture and marked spasticity subsequently developed. The initial MRI examination showed diffuse involvement of white matter, including subcortical U-fibers, with signal intensity parallel to CSF on all sequences. The white matter appeared swollen. The ventricles were slightly enlarged and there was cavum septi pellucidi et vergae. The posterior crus of the internal capsule, external and extreme capsules were affected. Cerebellar hemispheres and vermis showed atrophy. The involvement pattern of brainstem was noteworthy in that pontine tegmentum and cruri cerebri were affected. Follow-up MRI obtained after three years did not show any interval change. Brain biopsy showed thinned cortex with relatively preserved cortical layering and neuronal structure. There was rarefaction of the white matter with cystic degeneration. Fibrillary gliosis and increased number of oligodendroglial cells were observed within the cerebral white matter.

Arylsulfatase A pseudodeficiency incidence in Turkey

Pseudodeficiency (Pd) in arylsulfatase A (ASA) is a relatively frequent condition in healthy individuals. It produces a reduction in enzyme activity similar to that found in metachromatic leukodystrophy (MLD). A variable incidence of the Pd allele was found in different populations; it was 10-20 times higher than that of metachromatic leukodystrophy. Twelve of the 52 unrelated, healthy individuals were found to be heterozygous for the ASA Pd allele. In Turkey we estimated the incidence of the Pd allele as 11.5 percent. Out of 18 cases with MLD, one patient was found homozygous for the Pd allele and the other patient was found heterozygous.

Effect of alendronate treatment on the clinical picture and bone turnover markers in chronic idiopathic hyperphosphatasia

Chronic idiopathic hyperphosphatasia (CIH), also known as juvenile Paget's disease, is characterized by increased bone turnover, persistently elevated serum alkaline phosphatase concentrations and progressive bone deformities. The pathogenesis of the disease is unknown. Currently, there is no specific treatment and agents that reduce bone turnover have been tried in some cases with limited success. In this report, we present our experience with alendronate treatment in a 17 year-old boy with CIH. Ten weeks of treatment with alendronate resulted in marked clinical improvement and normalization of serum alkaline phosphatase activity. Serum osteocalcin and urinary deoxypyridinoline levels were decreased approximately 50% compared to pretreatment values, indicating decreased bone turnover rate. Alendronate seems to be a promising and safe agent for treatment of CIH.

Leigh syndrome in a 3-year-old boy with unusual brain MR imaging and pathologic findings

We report unusual MR serial imaging and electron microscopy findings in a 3-year-old boy who had Leigh syndrome with cytochrome-c oxidase (cox) deficiency. The MR imaging findings included periventricular white matter involvement, posteroanterior progression, and extension through the corpus callosum and internal capsule; however, no basal ganglia or brain stem abnormality was found, which was suggestive of leukodystrophy. The most noteworthy findings were the cystic foci with contrast enhancement in the affected white matter.

Effect of botulinum toxin injections into rabbit eye

The aim of this study was to investigate the adverse effects of the intraocular injection of botulinum toxin in rabbits. Intravitreal injections of botulinum toxin A in five doses, 1.25, 2.5, 5, 10, 25 units, were given into five rabbit eyes. The same volume of saline was injected into the second eye of the rabbit as a control. External examination, ophthalmoscopy, visual evoked potentials and electroretinography were done before injection and repeated at the first and second weeks after the injection. There were no significant differences in retinal function between toxin- and saline-injected eyes, neither ophthalmoscopically nor electrophysiologically. Ipsilateral mydriasis developed in the eyes injected with botulinum toxin. This study suggests that botulinum toxin has no harmful effect on retinal function.

Rasmussen encephalitis in childhood

Six patients admitted to the Department of Pediatric Neurology at Hacettepe University Children's Hospital between 1992 and 1997 with a clinical diagnosis of Rasmussen encephalitis received surgical treatment for their intractable epilepsy. MRI, SPECT and WADA tests were performed in patients with an epileptic focus demonstrated on routine or long-term video EEG monitoring. Viral studies using the PCR methodology were performed in cases with histopathological evidence of Rasmussen encephalitis. The ages of these patients ranged between 7 and 16 years, and the mean age at onset of seizures was 7.1+/-2.2 years. In four patients seizures presented as epilepsia partialis continua and were refractory to anticonvulsive drug therapy. In three cases intravenous immunoglobulin therapy yielded temporary and partial improvement in seizure control. The mean presurgical follow-up duration was 2.04+1.74 years, and early surgical intervention for epilepsy was performed in one case. The surgical approach selected for the treatment of epilepsy was resective surgery with electrocorticography. The mean postoperative follow-up duration was 32.3+17.2 months. Seizures were fully controlled in one patient, in whom surgery was performed 3 months after the seizures first started. Early surgical intervention may provide histopathological evidence for diagnosis as well as effective seizure control.

A Turkish family with Greig cephalopolysyndactyly syndrome

Greig cephalopolysyndactyly syndrome is a very rare autosomal dominant disease characterized by postaxial polysyndactyly of hands, preaxial polysyndactyly of feet and peculiar facial features, and has been shown to be due to mutations in the GLI3 gene. We present clinical findings of a 39-year-old man and his nine-day-old daughter with Greig cephalopolysyndactyly who showed variable expression with regard to syndactyly of fingers and toes. The role of obstetric ultrasonography in the prenatal diagnosis of the syndrome is also discussed.

A case of paroxysmal tonic upgaze of childhood with ataxia

Paroxysmal tonic upgaze of childhood is a rare, distinctive, childhood syndrome that may be associated with ataxia and sometimes strabismus or amblyopia. Neurological examination as well as metabolic studies, electroencephalogram and neuroradiological investigations are normal in these patients. Although it has been considered as an age-related, dopa-sensitive dystonia, the exact pathogenetic mechanism is still unknown. Aggravation of attacks by fatigue, intercurrent infection or vaccination, and possible corticomesencephalic dysmaturation may underlie this abnormality. We report on a sporadic case of paroxysmal tonic upgaze with ataxia in which there was prompt aggravation of symptoms with sleep without response to levodopa treatment. This case suggests a different underlying pathogenetic mechanism from dopaminergic pathways for this syndrome.

Clinical observations in autosomal recessive spastic paraplegia in childhood and further evidence for genetic heterogeneity

Among our 23 families (32 cases) with autosomal recessive hereditary spastic paraplegia (AR-HSP) all presenting in childhood, 9 families had the "pure" form. Occasional patients with this form had upper extremity hyperreflexia, pes cavus and sphincter disturbances, even at the early stages. Fourteen families were classified as the "complicated" types which manifested with mental retardation and cerebellar abnormalities. The evolution and severity was variable, but was generally consistent within families. Carriers (parents) did not manifest any signs. A total of 5 multiplex families with "complicated" type were used to test for a genetic heterogeneity to the region on chromosome 8p12-q13 where the "pure" AR-HSP has been mapped previously. No evidence in favor of linkage was detected in 3 of our families, thus we further supported genetic heterogeneity for AR-HSP.

Sandhoff disease in the Turkish population

Eighteen cases affected by Sandhoff disease were investigated by an enzymatic study of serum and leukocytes during the period 1988-1996, the clinical expression and enzymatic study were reported and discussed. An indirect minimum disease incidence was calculated in the Turkish population. Hexosaminidase activity in serum and leukocytes was severely deficient when measured by synthetic substrate 4-MU-N-acetylglucosaminide using the thermolabile fractionation procedure. Fractionation of hexosaminidase revealed different levels of isoenzymes A and B. Clinically, organomegaly was not found in 11 out of 18 infantile Sandhoff disease patients, while the remaining seven had mild organomegaly. Organomegaly was not found in patients with relatively high % hexosaminidase B activities. These results suggested that patients with different percent heat-stable enzyme activity may have a different type of mutation which is related to the underlying molecular heterogeneity in the Turkish population where 21% of marriages are found to be consanguineous.

Long-term follow-up of indirect hyperbilirubinemia in full-term Turkish infants

OBJECTIVE

This retrospective follow-up study was performed to evaluate the suitability of the recently reported exchange transfusion limits (serum indirect bilirubin level of 428-496 mumol/1, 25-29 mg/dl) for Turkey.

MATERIAL AND METHODS

The study groups totalled 102 children, 8-13 years of age, who had been born at term with birthweights greater than 3000 g and had been treated for indirect hyperbilirubinemia during their newborn period; the control group consisted of 27 children of the same age-group without indirect hyperbilirubinemia. Children were grouped according to their maximum serum and bilirubin levels and direct Coomb's test results. Physical and neurological examinations, visual and brainstem auditory evoked potentials and the Wechsler Intelligence Scale for children--Revised for Turkish Children were performed.

RESULTS

There was no difference between the groups with regard to mean visual and brainstem auditory evoked potential latencies. Children whose direct Coomb's tests were positive had significantly lower IQ scores and more prominent neurological abnormalities (p < 0.05). IQ scores and prominent neurological abnormalities did not differ among the other groups. Nine children had prominent neurological abnormalities associated with abnormal brainstem auditory evoked potentials. An important risk factor was the duration that the infant's serum indirect bilirubin level remained greater than 342 mumol/l (20 mg/dl).

CONCLUSION

The current limit of 342 mumol/l should continue to be used for infants whose direct Coomb's tests are positive in our country. Until better criteria for exchange transfusion other than the indirect bilirubin level are established, the current limits should also still be followed for infants whose direct Coomb's tests are negative in Turkey, where regular neonatal follow-up examinations are not satisfactory.

Cockayne syndrome: review of 25 cases

Clinical and laboratory findings of 25 patients with classical Cockayne syndrome (CS) are reviewed. A history of consanguinity was present in 21 patients, and 15 patients had at least 1 affected sibling. Apart from the cardinal features of dwarfism, microcephaly, and mental retardation, the most consistent clinical features included photosensitivity (84%), gait disturbances (84%), progeroid appearance (84%), and ocular abnormalities (88%). The most consistent laboratory findings comprised abnormal nerve conduction (slowed conduction in 13 of the 16 cases with an ENMG), and an abnormal brainstem auditory evoked response (BAER) and/or audiometry (abnormal in 13 of the 17 cases in whom either one of them were available). Cerebral atrophy and calcification of the basal ganglia were the next more common laboratory findings. Clinical criteria are useful in most instances in the diagnosis of CS. In patients in whom the clinical features are controversial for a diagnosis of Cockayne syndrome, studies directed to disorders of myelination involving both peripheral and central nervous systems in conjunction with audiometry may aid in the diagnosis.

Clinical and magnetic resonance imaging features of L-2-hydroxyglutaric acidemia: report of three cases in comparison with Canavan disease

We report three cases of L-2-hydroxyglutaric acidemia and three cases of Canavan disease. The L-2-hydroxyglutaric acidemia cases are the first biochemically proven Turkish cases. Magnetic resonance imaging findings in the cases and similarities between the two diseases are emphasized. Both diseases are characterized by predominant subcortical white-matter involvement and dentate nuclei lesions with variable basal ganglia involvement. Canavan disease differs from L-2-hydroxyglutaric acidemia by the presence of typical brainstem involvement.

Myasthenia gravis in childhood

Clinical features, serum acetylcholine receptor antibody (AChRAb) titres and course were reviewed in a series of 25 congenital (CMG) and 30 juvenile (JMG) myasthenia gravis cases to recognize characteristics of childhood-onset myasthenia and its subgroups. The initial symptom for CMG is ptosis accompanied or followed by generalized weakness; myasthenic crises do not occur and spontaneous remissions are rare. In JMG, the distribution of weakness remains the same, but the severity fluctuates: spontaneous remissions (6 patients) and myasthenic crises (10 patients) are observed. Good response to anticholinesterase drugs is slightly more frequent in JMG (62 versus 41%). AChRAbs were present in 9/26 JMG tested, girls with onset after 11 years being more likely to be Ab-positive. Since patients with autoimmune myasthenia and a young age of onset are often seronegative, clinical features such as changing distribution of weakness, fluctuating severity, or response to treatment might be considered as supportive criteria for differentiating JMG from CMG.

Applying critical pressure to middle cerebral artery in dogs

The purpose of our model was to provide maximum pressure level of the middle cerebral artery (MCA) without causing any histological variation like focal cerebral ischaemia. In this experimental study 9 dogs were used. A modified Spetzler occluder was applied to the MCA of the dogs to determine regional cerebral blood flow (rCBF) and somatosensory evoked potentials (SSEP). Seven animals underwent the surgical procedure with measurements of rCBF after arterial microdissection and then after applying 80% blood pressure (BP) to the MCA for 15 minutes. In rCBF a 29% average reduction was observed. The average value of rCBF at the end of 15 minutes was 63.5 +/- 6.52 ml/100g min. Simultaneous somatosensory evoked potential recordings were also obtained. When rCBF was reduced 29%, 80% BP applying to MCA did not cause complications.

Intestinal lymphangiectasia in a patient with Zellweger cerebrohepatorenal syndrome

Zellweger cerebrohepatorenal syndrome (ZWCHRS) is an autosomal-recessive disease, characterized by the absence or profound deficiency of peroxisomes. We report a case of ZWCHRS with intestinal lymphangiectasia, observed as an autopsy finding. This combination is previously unreported.

Griscelli syndrome: report of three cases

The clinical features of three children with Griscelli syndrome and autopsy findings of two are presented. The patients were 5 years, 9 months, and 3 months old, respectively. Clinical features included partial albinism, hepatosplenomegaly, and various neurological symptoms. Light and electron microscopic studies of the skin were compatible with Griscelli syndrome. Postmortem examination of the viscera and central nervous system revealed lymphohistiocytic infiltration with erythrophagocytosis. Bilateral diffuse involvement of the central nervous system, cranial nerve, and spinal cord was detected in both cases.

Multicentric angiofollicular lymph-node hyperplasia associated with myasthenia gravis

Castleman's disease is often referred to as giant lymph-node hyperplasia. Although this localized disorder most commonly involves the mediastinum, recently many patients have been described with multicentric lymph-node hyperplasia associated with various clinical abnormalities. Here a new case of multicentric angiofollicular lymph-node hyperplasia associated with myasthenia gravis and gammopathy is presented. At first, the patient responded to surgery well, but after some months her condition deteriorated: plasmapheresis was then performed, one year after the operation, with great clinical improvement.

A study on enzyme activities of some sphingolipidoses

Enzyme activities were determined in fibroblast cell cultures of eight patients suspected of having a type of sphingolipidosis. The patients were 0 to 4 years of age; four were female and four were male. Thirteen age-matched controls were also included in the study. In one of the cases, hexosaminidase A activity was found to be 0% (43-82%), while in two other cases beta-galactosidase activity was found to be 5 nmol/h/mg protein (100-1035 nmol/h/mg protein) and arylsulfatase activity was found to be 12 nmol/h/mg protein (106-990 nmol/h/mg protein), respectively. Two more enzymes, alpha-galactosidase (11-39 nmol/h/mg protein) and cerebroside beta-galactosidase (3.7-6.9 nmol/h/mg protein), were also evaluated but were found to be in the normal ranges in these patients. Therefore, these patients were considered to have Tay-Sachs disease, GM1 gangliosidosis and metachromatic leukodystrophy, respectively. The remaining five patients were normal in respect to the five enzyme activities determined. For the prenatal diagnosis of metachromatic leukodystrophy, arylsulfatase A activity was determined in one amniotic cell culture. The activity found in this case was lower than normal (34 nmol/h/mg protein versus 387 nmol/h/mg protein found in three control amniotic cell cultures.

Analysis of "pure" congenital muscular dystrophies in thirty-eight cases. How different is the classical type 1 from the occidental type cerebromuscular dystrophy?

Congenital muscular dystrophies (CMD) are heterogenous in clinical and pathologic manifestations. The "pure" classical form includes cases without severe impairment of intellectual development (Type 1), and cases with normal or subnormal IQ which show white matter hypodensity on CT scan examination. This latter group is sometimes called the "occidental type cerebro-muscular dystrophy" (OCMD). In this study we report clinical and pathologic findings in 38 cases with pure CMD. Eighteen of them were classified as Type 1 and 20 as OCMD, following the neuroradiological work-up. Statistical analysis between the two groups were done for: age range, consanguinity, multiple joint contractures, maximal motor capacity, facial involvement, high CK, endomysial fibrosis, adiposis, fiber atrophy and necrosis. CK was significantly higher in the OCMD group. Though not statistically significant, multiple joint contractures and muscle fiber necrosis were seen in more OCMD patients. These parameters denoted severity. The results of electrophysiological tests did not show any statistical differences. In pure CMDs there is evidence for overlap between the two sub-groups. OCMD cases may tend to run a more severe course in the presence of significantly higher CK levels.

Neurologic features as initial presentations of childhood malignancies

Thirty patients were examined initially because of neurologic problems and later were diagnosed as having systemic malignant disorders. Acute leukemia was the most common malignancy (36.6%), followed by neuroblastoma (33.3%), non-Hodgkin lymphoma (13.3%), rhabdomyosarcoma (10%), Ewing tumor (3.3%), and Hodgkin lymphoma (3.3%). Four of the 11 acute leukemia patients had nervous system involvement due to meningeal, orbital, or cerebellar infiltration. The complaints of the remaining patients included back pain, weakness, and difficulty in walking, all of which were caused by anemia or bone pain. Neurologic involvement in systemic malignancies, other than acute leukemia, mainly appeared as spinal cord compression (7 with neuroblastoma, 3 non-Hodgkin lymphoma, 1 rhabdomyosarcoma, 1 Ewing tumor), orbital or cavernous sinus infiltration (3 with acute leukemia, 1 rhabdomyosarcoma), and VIIth cranial nerve involvement (2 with rhabdomyosarcoma). One patient had skull infiltration without any neurologic deficit. Cerebellar signs were caused by the remote effects of cancer. It is concluded that acute leukemia is the first and neuroblastoma is the second most common malignancy among childhood systemic malignancies presenting with neurologic involvement; however, neuroblastoma is the most common cause of spinal cord compression.

Dermoid tumor with persistently low CSF glucose and unusual CT and MRI findings

A patient with dermoid tumor, presenting with persistent hypoglycorrhachia in the absence of cerebrospinal fluid pleocytosis is reported. The presence of ring enhancements without infection, surrounding edema, and mass effect on computed tomography and magnetic resonance imaging are unusual findings for these tumors.

Multiple sclerosis in a six-year-old boy (case report)

A 6-year-old boy with multiple sclerosis, youngest diagnosed in our hospital, is presented. In addition to the clinical findings, the diagnosis was supported by increased immunoglobulin levels, positive IgG index and oligoclonal bands in the cerebrospinal fluid, normal cranial angiography, typical lesions on the cranial computed tomography and magnetic resonance imaging.

Moyamoya disease and alternating hemiplegia. A report of two cases

Moyamoya disease is one of the cerebrovascular disorders and is characterized by bilateral stenosis or occlusion of the distal internal carotid arteries and their main branches. Repeated ischemic episodes in children and intracranial hemorrhage in adults with moyamoya disease is usually noted. In this report, we describe two children with moyamoya disease who presented with alternating hemiplegia. The final diagnosis was made by cerebral angiography and cranial computed tomography in these patients. Other neurological and radiological features of the patients were described.

Improvement of myotonia with carbamazepine in three cases with the Schwartz-Jampel syndrome

Carbamazepine was used as an anti-myotonic agent in three cases with the Schwartz-Jampel syndrome. Clinical myotonia, blepharospasm and a five-stair climbing test improved significantly within two to four months of the initiation of the medication. In the two cases which were followed three and two years, height shifted from under the 3rd centile to the 5th. Carbamazepine may be a drug of choice in the Schwartz-Jampel syndrome.

An unusual case of Duchenne muscular dystrophy

A 10-year-old boy with Duchenne muscular dystrophy (DMD), with quite unusual clinical data, is presented. He was unable to walk until age 6, walked only for 9 months and then became wheel-chair bound. No dystrophin was present on muscle biopsy sections and a large deletion was found in the dystrophin gene. The deletion encompassed the central high frequency deletion region of the gene. Early developmental milestones may be delayed in DMD, but patients usually start to walk around 2-3 years of age. A delay of the extent in this case is very unusual.

Evoked potentials in Guillain-Barré syndrome

A prospective evaluation was made in a total of 19 patients with Guillain-Barré syndrome (GBS) by neurologic examination, visual evoked potentials (VEP), brain-stem auditory evoked potentials (BAEP) and somatosensory evoked potentials (SEP) during the acute phase of the disease, three weeks later, and then again three months after the onset of symptoms. The results of electrophysiologic studies of the patients were compared with those of 19 healthy children. There were no statistically significant differences found in the mean VEP and BAEP values between the patient and control groups. However, the VEP and BAEP values were abnormal during the first and second stages of the disease in only a few patients. There was a statistically significant prolongation of the response in tibial and median SEP during the first and second stages of the disease when compared with the third stage and the control group. The Erb-Cervical 7 (C7) interwave latency was elevated in the median SEP. It was concluded that the prolongation of the response in SEP was diagnostically important in the acute phase of GBS. There was no correlation found between SEP and clinical progression.

Evoked potentials in full-term and premature infants: a comparative study

In this study the maturation of the central nervous system of full-term and premature infants were investigated electrophysiologically. The subjects were 16 full-term and 15 premature infants. Neurologic examination, psychometric tests, and measurement of evoked potentials were carried out periodically in babies who had no birth trauma, metabolic disorder, or intrauterine infection. Neurophysiologic comparison of the results was evaluated. As the babies grew older, I-V interpeak latency became shorter according to the results of brainstem auditory evoked potentials; N1-P1 amplitude became higher and P1 latency shorter according to the results of visual evoked potentials. Central nervous system maturation of full-term babies and prematures appear to be alike at 6 months of age.

Neurophysiological studies of patients with classical phenylketonuria: evaluation of results of IQ scores, EEG and evoked potentials

Neurophysiological studies were conducted in 42 patients with classical phenylketonuria. The results of the intelligence quotient scores, electroencephalogram, visual evoked potentials and brain-stem auditory evoked potentials were evaluated. When compared with the controls, the subjects demonstrated a significant prolongation in VEP P1 and BAEP I-V interpeak latencies and an increase in VEP N1P1 amplitudes. No relationship was found between these pathological responses and metabolic control. However, the observation of normal intelligence quotient scores in 14 out of 18 patients who displayed a pathological prolongation in P1 latencies led us to the conclusion that evoked potentials may have a significant role in the determination of neurophysiological defects and that even cases with good metabolic control may have some obscure neurophysiological dysfunction which should be evaluated more carefully.

Deletion analysis of Duchenne muscular dystrophy

DNA of 15 patients with Duchenne muscular dystrophy (DMD) were analyzed for deletions within the DMD gene by using recombinant DNA technology. Deletion frequency was 47 percent and six of the deletions occurred in the region of probe 7 + 8. Only one of the deletions was observed in the region of probe 9-7, and no deletions were found in the region of probe 30-1, 30-2 and 47-4 (5b + 6). The frequency of deletions found in the Turkish DMD patients corresponds to frequencies reported for other populations.

Selective involvement of the quadriceps muscle in congenital muscular dystrophies: an ultrasonographic study

Muscle ultrasound scanning is a non-invasive and painless technique for evaluating muscle disorders in childhood. We have performed ultrasound scans of the quadriceps muscle in 26 children with various forms of congenital muscular dystrophies. There were 8 patients clearly showing selective involvement within the components of the quadriceps. In all cases showing selective involvement, the rectus femoris was spared and the vastus muscles were the affected group. Our findings support the concept of heterogeneity, often encountered in congenital muscular dystrophies.

Primary intracranial extradural Burkitt-type lymphoma. A unique presentation with unilateral loss of vision in a child

An unusual case of primary extranodal Burkitt's-type lymphoma of the frontal base dura and adjacent bone with intradural invasion is reported in a 5-year-old child who presented with unilateral loss of vision in the left eye. Tissue diagnosis was obtained through a craniotomy and the patient received radiotherapy plus intravenous and intrathecal chemotherapy. The tumor regression and improvement in vision was well documented by means of CT and visual evoked potential studies (VEP). A review of the literature on this exceptionally rare tumor is presented.

N-acetylaspartic aciduria in Canavan disease: another proof in two infants

Increased amounts of urinary N-acetyl-aspartic acid was found in two infants with biopsy proven Canavan disease. The aspartoacylase assay is a new tool for determining both the prenatal and antenatal diagnosis of Canavan disease. This assay should be screened in patients with early onset of psychomotor deterioration, macrocephaly, spasticity/hypotonia and white matter hyperleucency at CT scan.

[Treatment of infectious endocarditis with trimethoprim-sulfamethoxazole and cardiac surgery]

A 12 year old boy was admitted to hospital with fever, general malaise, cough and peripheral edema. The patient who have had rheumatic heart diseases-mitral insufficiency was found to be in congestive cardiac failure. In blood cultures Staphylococcus aureus and Alpha-hemolytic streptococcus grew. The regimens of Cephalothin-Gentamicin, Methicillin-Tobramicin, to which the organism were sensitive were given intravenously. On these therapy the patient continued to have fever. He was put on Trimethoprim-Sulfomethoxazole intramuscularly. He became afebril for the first time. After two weeks fever recurred. In spite of medical treatment, the infection persisted and the indication for surgery was considered. Mitral valve replacement with a Starr-Edwards prosthesis was carried out. Postoperatively, the patient was treated with TMP-SMZ. For the past 10 months the patient has remained afebril and without evidence of congestive heart failure.