POMT1-associated walker-warburg syndrome: a disorder of dendritic development of neocortical neurons.

We have analyzed the morphology and dendritic development of neocortical neurons in a 2.5-month-old infant with Walker-Warburg syndrome homozygotic for a novel POMT1 gene mutation, by Golgi methods. We found that pyramidal neurons frequently displayed abnormal (oblique, horizontal, or inverted) orientation. A novel finding of this study is that members of the same population of pyramidal neurons display different stages of development of their dendritic arborizations: some neurons had poorly developed dendrites and thus resembled pyramidal neurons of the late fetal cortex; for some neurons, the level of differentiation corresponded to that in the newborn cortex; finally, some neurons had quite elaborate dendritic trees as expected for the cortex of 2.5-month-old infant. In addition, apical dendrites of many pyramidal neurons were conspiciously bent to one side, irrespective to the general orientation of the pyramidal neuron. These findings suggest that Walker-Warburg lissencephaly is characterized by two hitherto unnoticed pathogenetic changes in the cerebral cortex: (a) heterochronic decoupling of dendritic maturation within the same neuronal population (with some members significantly lagging behind the normal maturational schedule) and (b) anisotropically distorted shaping of dendritic trees, probably caused by patchy displacement of molecular guidance cues for dendrites in the malformed cortex.

Fumaric aciduria: mild phenotype in a 8-year-old girl with novel mutations.

Fumaric aciduria is a rare, autosomal recessive disorder caused by deficient activity of fumarate hydratase (FH). Common clinical features are hypotonia, failure to thrive, severe psychomotor retardation and seizures. Facial dysmorphism and brain malformations are frequent. Recently, some FH gene mutations have been associated with inherited cutaneous and uterine leiomyomas and papillary renal cell cancer. Our patient had a relatively mild phenotype, a previously not reported genotype and familial tumour predisposition. The mother and grandmother had uterine myomas. The paternal grandfather and his two brothers died from lung and laryngeal cancers. The pregnancy was complicated by bleeding and intrauterine growth retardation. Delivery was after 35 weeks, with normal Apgar score. The girl was hypotonic since birth. At age 2 months the parents noticed short apnoeic crises. She could sit at age 1.5 years, and walk with assistance at 4 years. At age 8 years highly increased excretion of fumaric acid was found twice (217 and 445 mmol/mol creatinine). Shortly before that the girl started to have leg and arm spasms. Grand mal seizures occurred twice. Facial dysmorphism included depressed nasal bridge, anteverted ears, hypertelorism and microcephaly. Speech was limited to few disyllables. She was atactic with spastic paraparesis. Brain MRI showed slight ventriculomegaly, white-matter atrophy and hypoplasia of corpus callosum. Activity of FH in fibroblasts was 1.9 nmol/min/mg protein (controls 40-80). Analysis of the FH gene revealed the maternally derived c.1029_1031delAGT mutation, resulting in Val deletion and substitution of Gln by His, and paternally derived c.976C > T mutation, resulting in substitution of Pro by Ser.

S-Adenosylhomocysteine hydrolase deficiency: a second patient, the younger brother of the index patient, and outcomes during therapy.

S-Adenosylhomocysteine (AdoHcy) hydrolase deficiency has been proven in a human only once, in a recently described Croatian boy. Here we report the clinical course and biochemical abnormalities of the younger brother of this proband. This younger brother has the same two mutations in the gene encoding AdoHcy hydrolase, and has been monitored since birth. We report, as well, outcomes during therapy for both patients. The information obtained suggests that the disease starts in utero and is characterized primarily by neuromuscular symptomatology (hypotonia, sluggishness, psychomotor delay, absent tendon reflexes, delayed myelination). The laboratory abnormalities are markedly increased creatine kinase and elevated aminotransferases, as well as specific amino acid aberrations that pinpoint the aetiology. The latter include, most importantly, markedly elevated plasma AdoHcy. Plasma S-adenosylmethionine (AdoMet) is also elevated, as is methionine (although the hypermethioninaemia may be absent or nonsignificant in the first weeks of life). The disease seems to be at least to some extent treatable, as shown by improved myelination and psychomotor development during dietary methionine restriction and supplementation with creatine and phosphatidylcholine.

Croatia has reached iodine sufficiency.

This study was performed in 2002, 6 yr after the introduction of a new regulation on salt iodination with 25 mg KI/kg of salt. The aim of the study was to evaluate whether further significant positive results of improved iodine intake could be observed among schoolchildren in Croatia. A total of 927 schoolchildren of both sexes, aged 6-12 yr, were included in the study. In Croatia, with a population of 4,437,460 the research was implemented in four major geographical regions: the Northwestern, Slavonia, Northern Adriatic and Dalmatian regions. Investigations included randomly selected pupils from regional centers and neighboring smaller towns or villages. The results have revealed that thyroid volumes were within the normal range according to the provisional WHO/ICCIDD reference values for sonographic thyroid volume in iodine-replete school-age children, updated in 2001. A significant improvement in medians of urinary iodine excretion was detected in 2002: from 9 microg/dl in 1991 to 14.6 microg/dl in Zagreb, from 4.3 microg/dl in 1995 to 13.1 microg/dl in Split, from 9.4 microg/dl in 1997 to 14.2 microg/dl in Rijeka and from 13.4 microg/dl in 1997 to 14.7 microg/dl in Osijek. An overall median of 14.0 microg/dl of urinary iodine excretion was detected in Croatian schoolchildren. The control of salt at different levels, from production to consumption, including salt produced in all three Croatian salt plants and imported salt, revealed that Croatian salt is adequately iodized. From severe iodine deficiency before the 1950s, through mild-to-moderate iodine deficiency in the 1990s, Croatia has now reached iodine sufficiency.

Molecular analysis and electromyoneurographic abnormalities in Croatian children with proximal spinal muscular atrophies.

Childhood onset proximal spinal muscular atrophy presents with considerable clinical variability. This study included 14 Croatian children aged 11 days to 8 years with spinal muscular atrophy types I-III verified clinically and electromyoneurographically. DNA of affected children was screened for deletions of exons 7 and 8 of the survival motor neuron gene and for deletion of exon 5 of the neuronal apoptosis inhibitor protein gene. Motor nerve conduction velocity and compound muscle action potential amplitude were decreased in children with spinal muscular atrophy type I and II. Deletions of exons 7 and 8 of the survival motor neuron gene and of exon 5 of the neuronal apoptosis inhibitor protein gene in children with spinal muscular atrophy type I-II suggested existence of more genetic abnormalities as compared to type III. A decrease in compound muscle action potential amplitude and motor nerve conduction velocity in children with spinal muscular atrophy correlated with the disease severity, probably as a result of axonal degeneration. Phenotypic severity in children onset spinal muscular atrophy is directly correlated with the extent of survival motor neuron and neuronal apoptosis inhibitor protein exon deletions.

Partial trisomy 13 in an infant with a mild phenotype: application of fluorescence in situ hybridization in cytogenetic syndromes.

We report on a month-old infant with dysmorphic face and several anomalies known to be associated with trisomy 13. Fluorescence in situ hybridization (FISH) studies performed on metaphase cells allowed us to identify an extra material on the short arm of the chromosome 13 as a duplication of 13q22-qter.

Complex disorder of neuronal migration in an infant with possible congenital cytomegalovirus infection.

A ten-months-old girl was evaluated for developmental delay, increased muscle tone and seizures. CT and MRI revealed un uncommon combination of two different manifestations of neuronal migration disturbance: agyria/pachygyria and subcortical laminar heterotopia ("double cortex" syndrome). The occurrence of these two manifestations of neuronal migration dosorders in the same individual is quite unusual. The possible pathogenesis of such a complex disorder could probably be established only by histologic examination of the brain. A positive serologic reaction for cytomegalovirus in the infant at the age of 11 months and in the mother suggested but did not prove the cytomegalovirus infection in early gestation as the cause of the disorder.

The role of plasma exchange in the treatment of severe forms of hemolytic-uremic syndrome in childhood.

Therapeutic plasma exchange (PE) or plasma-pheresis has been used in recent years in the treatment of severe hemolytic uremic syndrome (HUS) in children. We analyzed the benefit of PE and peritoneal dialysis (PD) in 9 children, 6 boys and 3 girls, aged 1-10 years, from 1983-1993. All children came from different geographical regions, and all had the sporadic form of the illness. Three patients had the gastrointestinal form, 5 had respiratory prodromes while 1 child developed HUS during the course of varicella. Seven children were hypertensive, but only in 3 was hypertension persistent. The child with varicella had a transient complement decrease. Five children were treated with PE. In 4 children, fresh frozen plasma (FFP) was used as replacement fluid, and human albumin was used in 1 child. Four children were treated with PD and infusions of FFP. Rapid recovery of renal function was observed in 5 patients whereas in 2 oliguric children the recovery of renal function ensued within 1 and 2 months, respectively. Two children developed terminal renal failure (TRF) (in 1 child the treatment was very delayed, and in other child HUS developed following varicella). Only 1 boy had relapses of the disease followed by impairment of renal function from which he gradually recovered. During the 3-10 year follow-up period, only the child with relapses was hypertensive while the others had normal clinical and laboratory parameters. We suggest that PE plays an important role in the early treatment of severe forms of HUS in children.

Haplotype distribution and mutations at the PAH locus in Croatia.

Restriction fragment length polymorphism (RFLP) haplotypes and mutations at the phenylalanine hydroxylase (PAH) locus have been studied in 25 unrelated families from Croatia. The results of RFLP analysis demonstrated that 80% of the mutant alleles were associated with three haplotypes (1, 2 and 4). Eight mutations were detected on the background of six mutant haplotypes, comprising 68% of phenylketonuria (PKU) alleles in Croatia. The mutation in codon 408 was most frequent, as was the haplotype 2 allele with which it was associated. These data are in accordance with formerly published population genetic analyses at the PAH locus, and with studies revealing the molecular basis of the phenotypic heterogeneity of PKU. The codon 281 mutation was more frequent in Croatia than previously observed in other populations.

Corticosterone methyloxydase deficiency type II in a Croatian girl.

This is a brief case report on a four-month-old girl who was admitted for failure to thrive and moderate dehydration. On admission she was mildly dehydrated and undernourished but with otherwise normal physical findings. Laboratory investigation disclosed mild but constant hyponatremia and hyperkalemia, very high plasma renin activity (greater than 900 ng/mL per hour) and low plasma aldosterone concentration (2.5 ng/dL). The plasma 18-hydroxycorticosterone (18-OH-B) was very high (1,682 ng/dL), producing thus an abnormally elevated 18-OH-B to aldosterone ratio of 542 (normally 6.3 +/- 3.6). The diagnosis of corticosterone methyloxydase deficiency type II was made, and the administration of fluorohydrocortisone resulted in rapid weight gain with normalization of blood electrolytes and gradual decrease in plasma renin activity. A very efficient catch-up growth resulted in normal body weight and length at the age of 2 years. This is the first well documented case of the disease in the population of Yugoslavia.

Adrenocorticotropic hormone insensitivity associated with autonomic nervous system disorders.

Five children with adrenocorticotropic hormone (ACTH) insensitivity associated with autonomic nervous system disorders are described. At the time of diagnosis, four of them had osteoporosis. The fifth patient died and skeletal roentgenograms were not done. Osteoporosis was subsequently discovered in one of our previously reported patients with ACTH insensitivity. We assume that osteoporosis is, at least partly, the result of decreased adrenal androgen production. Human leucocyte antigen typing failed to establish any linkage.

Immunological aspects of progeria (Hutchinson-Gilford syndrome) in a 15-month-old child.

A thorough analysis of the immunological status was conducted in a 15-month-old child with progeria (Hutchinson-Gilford syndrome). Total leukocyte and neutrophil counts were slightly increased, and monocytes were decreased. Percentage and numbers of CD4+ cells in the blood were mildly decreased as well as the CD4/CD8 cell ratio. CD20 (B-cell marker) bearing cells and cells bearing Ia-antigens were increased, as well as CD16 and CD56 marker-bearing cells (natural-killer cells, NK). Lymphocyte proliferation upon stimulation with phytohaemagglutinin and purified protein derivative were decreased, and with pokeweed mitogen increased. NK cell activity appeared increased, particularly at lower effector: target cell ratios.

[Inborn metabolic errors of urea cycle synthesis. Present possibilities of treatment]. / Prirodene greske u metabolickom ciklusu sinteze ureje. Suvremene mogucnosti lijecenja.

The case history of an infant with congenital hyperammonaemia due to inherited ornithine-transcarbamylase deficiency is presented together with some basic data on his family. The metabolic cycle of urea synthesis is delineated with its enzymes and the possible inherited defects. The differential diagnosis of hyperammonaemia in the newborn infant is given. The successful contemporary method of therapy of urea cycle disorders is presented.

Screening of newborns for congenital hypothyroidism in Croatia--organization and first results.

In 1985 a newborn screening programme for the detection of congenital hypothyreosis was introduced in Croatia in addition to the already existing one for phenylketonuria. The paper delineates the organization of the screening programme, the method used, and the first results. Clinical manifestations, somatic and mental development, as well as laboratory findings of the first eleven children with congenial hypothyroidism detected by the screening programme and followed-up regularly are presented in more detail.