Search

Hyperammonemic encephalopathy in newborns with urea cycle disorders and certain organic acidurias can cause severe brain injury, coma and death. Standard therapy includes protein restriction, nitrogen-scavenging drugs, prevention of catabolism and hemodialysis. Neuroprotective hypothermia as part of the treatment has been reported only 3 times. It has been suggested that mild systemic hypothermia can contribute to better neurological outcomes in hyperammonemic encephalopathy. However, the limited experience precludes accurate conclusions on safety and efficacy.Whole body therapeutic hypothermia was included in the standard treatment of hyperammonemic encephalopathy in 4 neonates with urea cycle disorder or organic aciduria.Two patients survived the initial crisis. One patient has a developmental quotient of 0.8, while the other shows severe developmental delay. The cooling protocol had to be discontinued in 3 patients due to the otherwise untreatable complications (hypotension and hemorrhage).The efficacy and safety of therapeutic hypothermia in the treatment of neonatal hyperammonemic encephalopathy depend on various factors, requiring further evaluation.Die hyperammonämische Enzephalopathie bei Neugeborenen mit Harnstoffzyklusstörungen und bestimmten organischen Azidämien kann zu schweren Hirnverletzungen, Koma und Tod führen. Die Standardbehandlung umfasst Proteinrestriktion, „Stickstoff-fangenden“ Medikamente, Katabolismusprävention und die Hämodialyse. Die neuroprotektive Hypothermie wurde als Teil der Behandlung nur 3-mal berichtet. Es wurde vorgeschlagen, dass die milde systemische Hypothermie für bessere neurologische Ergebnisse bei der hyperammonämischen Enzephalopathie beitragen kann. Die begrenzte Erfahrung schließt jedoch die genauen Schlussfolgerungen zu Sicherheit und Wirksamkeit aus.Bei 4 Neugeborenen mit Harnstoffzyklusstörung oder organischer Azidämie wurde die Ganzkörper-Hypothermie in die Standardbehandlung der hyperammonämischen Enzephalopathie eingezogen.Zwei Patienten überlebten die erste Krise. Ein Patient hat einen Entwicklungsquotient von 0,8, während der andere schwere Entwicklungsverzögerung zeigt. Das Kühlungsprotokoll musste bei 3 Patienten wegen der nicht behandelbaren Komplikationen (niedriger Blutdruck und Blutungen) abgebrochen werden.Die Wirksamkeit und Sicherheit der therapeutischen Hypothermie bei der Behandlung der neonatalen hyperammonämischen Enzephalopathie hängt von verschiedenen Faktoren ab, die eine weitere Evaluierung erfordern.

Background: Classic galactosemia is an autosomal recessive disorder of galactose metabolism caused by severely decreased activity of galactose-1-phosphate uridylyltransferase (GALT) due to pathogenic mutations in the GALT gene. To date more than 330 mutations have been described, with p.Q188R and p.K285N being the most common in Caucasian populations. Although acute manifestations can be fully avoided by a galactose-restricted diet, chronic complications, such as neurological ones, cannot be prevented in a significant number of patients despite compliance with the dietary treatment. Methods: A cohort of 16 galactosemic Croatian patients, including one pair of siblings, was studied. Molecular characterization was performed by direct sequence analysis of the GALT gene. Results: Sixteen patients were analyzed and only four different mutations were detected. As expected, p.Q188R and p.K285N were common, accounting for 40% and 37% of unrelated alleles, respectively. The third mutation accounting for 20% of mutant alleles was p.R123X causing a premature stop codon, is thus considered to be severe, which is in accordance with the phenotype presented by the homozygous patient described here. The fourth mutation p.E271D was found in a single allele. More than half of our patients manifested some chronic neurological complications. Conclusions: This is the first report on mutational and phenotypic spectra of classic galactosemia in Croatia that expands the knowledge on the mutational map of the GALT gene across Europe and reveals the genetic homogeneity of the Croatian population.

The aim of our study was to assess the current state of newborn screening (NBS) in the region of southeastern Europe, as an example of a developing region, focusing also on future plans. Responses were obtained from 11 countries. Phenylketonuria screening was not introduced in four of 11 countries, while congenital hypothyroidism screening was not introduced in three of them ; extended NBS programs were non-existent. The primary challenges were identified. Implementation of NBS to developing countries worldwide should be considered as a priority.

Rijetke bolesti etiološki su heterogena skupina najčešće nasljednih, kroničnih i degenerativnih bolesti s pojavnošću manjom od 5 na 10 000 osoba. Poznato je više od 7000 rijetkih bolesti od kojih više od 600 ima osobitosti nasljednih metaboličkih poremećaja. Zbog velike kliničke heterogenosti i zahtjevnih dijagnostičkih testova put do konačne dijagnoze je često dug te uključuje i obradu u ino zemnim laboratorijima. Unatoč tome, dio bolesnika ostaje bez konačne dijagnoze. U situacijama kad je bolesnik vitalno ugrožen uz mogućnost letalnog ishoda i pri sumnji na nasljednu metaboličku bolest, biopsija kože je dio standardnog postupka. Posljednjih godina sve je više dostupnih mogućnosti liječenja za širok spektar nasljednih metaboličkih bolesti. Osnovni preduvjet za njihovu djelotvornost je pravodobna dijagnoza. Kultivirani kožni fi broblasti pohranjeni u biobanke vrijedan su biološki materijal. Osim za postavljanje dijagnoze, mogu se primijeniti i za provjeru djelotvornosti novih pristupa liječenju kao što su male molekule pratitelji. Sve navedeno upućuje na značenje organiziranja biobanke fi broblasta prema međunarodno prihvaćenim standardima., Rare diseases are an etiologically heterogeneous group of hereditary, chronic and degenerative disorders with the incidence lower than 5 per 10,000 individuals. More than 7,000 rare diseases have been identifi ed so far, and more than 600 of them have the characteristics of hereditary metabolic disorders. Due to the high clinical heterogeneity and demanding diagnostic tests, the path to fi nal diagnosis is often long and may also involve tests performed in laboratories abroad. Despite this, a number of patients remain without fi nal diagnosis. In life-threatening situations for the patient and in case of suspected hereditary metabolic disease, skin biopsy is part of the routinely performed standard procedure. Recent years have seen an increasing availability of treatment options for a broad range of hereditary metabolic diseases. The basic precondition for therapy effi cacy is timely diagnosis. Cultured skin fi broblasts that are stored in biobanks are a valuable biological material. Except for making diagnosis, they may be used to verify the effi cacy of novel approaches to treatment, e.g., small chaperon molecules. All of the above indicates the signifi cance of establishing a fi broblast biobank according to the internationally accepted standards.

Specific mutations in the gene encoding phenylalanine hydroxylase (PAH), located on chromosome 12q22-24.1, are linked to tetrahydrobiopterin (BH4; sapropterin)-responsive phenylketonuria (PKU). Diagnosis is usually done through the newborn screening for PKU, followed by a BH4 loading test. So far, more than 60 mutant alleles, presenting with a substantial residual PAH activity (average approximately 47%), were identified in more than 500 patients worldwide. We investigated the predictive value of BH4-responsive PAH mutations in Croatian population. From a group of 127 PKU patients, 62 were selected (based on the genotype) as potentially BH4-responsive and 39 loaded with BH4 (20 mg/kg). The overall frequency of BH4-responsiveness (30% blood phenylalanine reduction within 24 h) was 36% (14 out of 39 patients with 23 different genotypes), significantly less than expected. The best responders were patients with mild hyperphenylalaninemia (4/4; 100%), followed by mild PKU (8/9; 89%), and classical PKU (2/26; 8%). The most common BH(4)-responsive genotypes were p.E390G/p.R408W and p.P281L/p.E390G. These genotypes correspond for approximately30% residual PAH activity. The p.E390G mutation was 100% associated with BH4-responsiveness, regardless of the second allele (p.R408W, p.P281L, p.F55Lfs, p.L249P). With regard to the predicted relative PAH activity of recombinantly expressed mutant alleles, there was a significant (p0.002) difference between BH4-responders and non-responders. In a general Croatian PKU population, disease-causing mutations were identified on 226 alleles (99%). There were 35 different mutations: 21 missense, 8 splice site, 3 nonsense, 2 single nucleotide deletions, and 1 in-frame deletion. Four mutations are reported for the first time: p.E76D, p.L333P, p.G346E, and IVS8-2AG. Five mutations accounted for over two-thirds of investigated alleles: p.L48S, p.R261Q, p.P281L, p.E390G, and p.R408W. Thus, the Croatian PKU population seems to be more homogenous than some other Mediterranean or Central European populations. This study reveals the importance of a full genotype for the prediction of BH4-responsiveness. In contrast to previous assumption and with exception of the p.E390G mutation, single allele mutations are not reliable for the selection of potential PKU candidates for pharmacological therapy with BH4.

Hyperinsulinism-hyperammonemia (HI/HA) syndrome is a rare autosomal dominant disease characterized by recurrent hypoglycemia and persistent mild elevation of plasma ammonia. HI/HA syndrome is one of the more common forms of congenital hyperinsulinism (CHI), caused by activating mutations within the GLUD1 gene that encodes the mitochondrial enzyme glutamate dehydrogenase (GDH). We report here on monozygotic twin girls presented with fasting- and protein-induced hypoglycemia and mild persistent hyperammonemia. Genetic analysis revealed that both girls were heterozygous for a novel missense mutation within exon 11 [c.1499A>T, p.(R443W)] of the GLUD1 gene. Despite early treatment with diazoxide and a low protein diet, they both developed non-hypoglycemic seizures in early childhood followed by cognitive impairment. In addition to their clinical course, a review of the literature on HI/HA syndrome is provided.

Manjak lizosomske kisele lipaze autosomno je recesivno nasljedna bolest s dva klinička fenotipa. Wolmanova bolest počinje u ranoj dojenačkoj dobi i brzo je progresivna. Zbog masivnog nakupljanja kolesterolskih estera i triglicerida u crijevima, jetri, slezeni i drugim stanicama monocitno-makrofagnog reda dolazi do malapsorpcije, hepatosplenomegalije, zatajenja jetre i smrti u prvoj godini života. Bolest nakupljanja kolesterolskih estera može se očitovati od rane dječje do kasne odrasle dobi, varijabilna je tijeka i progresije. Glavna su obilježja različito izražena jetrena bolest, uključujući cirozu i zatajenje jetre, hiperkolesterolemija i rana ateroskleroza. Karakterističan je patohistološki nalaz mikrovezikularne steatoze i fibroze, a patognomoničan je ultrastrukturni nalaz kristala kolesterolskih estera. Dijagnozu potvrđuju mjerenje enzimske aktivnosti i/ili analiza gena. Liječenje je donedavno bilo suportivno i simptomatsko. Klinička istraživanja enzimskoga nadomjesnog liječenja pokazuju vrlo ohrabrujuće rezultate. Prikazujemo dojenče s Wolmanovom bolešću i dvoje djece s bolešću nakupljanja kolesterolskih estera s ciljem skretanja pozornosti na bolesti zbog manjka lizosomske kisele lipaze i što ranijeg početka optimalne skrbi., Lysosomal acid lipase deficiency is an autosomal recessive disorder with two distinct clinical phenotypes. Wolman disease is rapidly progressive with onset in early infancy. Complete enzyme deficiency results in massive accumulation of cholesterol esters and triglycerides in intestines, liver, spleen and other monocyte-macrophage system cells causing malabsorption, hepatosplenomegaly, liver failure and death in early infancy. Cholesterol ester storage disease may be diagnosed in childhood or later in life. It is characterized by chronic course and variable progression. Main features are variously expressed hepatopathy, including cirrhosis and liver failure, hypercholesterolemia and premature atherosclerosis. Characteristic is pathohistological finding of microvesicular steatosis and fibrosis and patognomonic are typical cholesterol ester crystals. Diagnosis is confirmed by enzyme assay and/or gene analysis. Until recently treatment was symptomatic. Ongoing clinical trials of enzyme replacement therapy have shown very promising results. We are presenting an infant with Wolman disease and two children with cholesterol ester storage disease with the aim to raise awareness about this disease and to start optimal care early.

Background We aimed to assess the current state of PKU screening and management in the region of southeastern Europe. Methods A survey was performed involving all identified professionals responsible for the PKU management in the 11 countries from South-Eastern region of Europe (Albania, Bulgaria, Bosnia and Herzegovina, Croatia, Kosovo, Macedonia, Moldova, Montenegro, Romania, Serbia, Slovenia). The questionnaire was designed to assess the characteristics regarding PKU management in three main areas: nation-wide characteristics, PKU screening, and characteristics of the PKU management in the responding centre. It consisted of 56 questions. The distribution and collection of the questionnaires (via e-mail) was taking place from December 2013 to March 2014. Results Responses from participants from 11 countries were included; the countries cumulative population is approx. 52.5 mio. PKU screening was not yet introduced in 4 of 11 countries. Reported PKU incidences ranged from 1/7325 to 1/39338 (and were not known for 5 countries). National PKU guidelines existed in 5 of 11 countries and 7 of 11 countries had PKU registry (registries included 40 to 194 patients). The number of PKU centers in each country varied from 1 to 6. Routine genetic diagnostics was reported in 4 of 11 countries. Most commonly used laboratory method to assess phenylalanine levels was fluorometric. Tetrahydrobiopterine was used in only 2 of 11 countries. Most frequently, pediatricians were caring for the patients. Dietitian was a member of PKU team in only 4 of 11 countries, while regular psychological assessments were performed in 6 of 11 countries. Patient’s PKU society existed in 7 of 11 countries. Conclusions The region of southeastern Europe was facing certain important challenges of PKU screening and management. Neonatal PKU screening should be introduced throughout the region. Furthermore, PKU management was falling behind internationally established standards-of-care in many aspects. Electronic supplementary material The online version of this article (doi:10.1186/s13023-015-0283-0) contains supplementary material, which is available to authorized users.

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.

Congenital hyperinsulinism (CHI) is a major cause of persistent hypoglycemia in the neonatal and early infancy periods. Althought the disease is relatively rare with incidence of about 1:25 000-50 000 live births, the importance of the disease should not be underestimated. Namely, prompt recognition and management of patients with CHI is essential, if permanent neurological impairment is to be avoided. CHI is caused by mutations in one of the 7 genes involved in the regulation of insulin secretion in pancreatic beta-cells. It is important to introduce specific medical therapy as soon as diagnosis is established. Severe, neonatal forms of CHI are often resistant to medications, thus they require surgical procedure. The preoperative genetic testing and scintigraphy are indicated to distinguish histological subtypes of the disease (focal vs. diffuse CHI). Patients with focal disease are usually cured after pancreatic resection, while diffuse disease has much worse prognosis. This manuscript offers novel insights into CHI and emphasizes the role of early diagnosis as crucial for succesful treatment that was recently enriched with novel options.

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 the 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.

Kongenitalni hiperinzulinizam (KHI) najčešći je uzrok tvrdokornih hipoglikemija u novorođenačkom i ranome dojenačkom razdoblju. Iako je bolest razmjerno rijetka s pojavnosti od oko 1 : 25 000–50 000 živorođene djece, bolest se ne smije podcijeniti zbog trajnih neuroloških oštećenja do kojih dolazi ako se bolest brzo ne otkrije i ne započne promptno liječiti. Uzrok su mutacije nekog od 7 gena, ključnih u regulaciji inzulinske sekrecije u b-stanicama gušterače. Odmah nakon postavljanja dijagnoze nužno je u terapiju uvesti antihipoglikemike koji djeluju specifično na -stanice gušterače. Kod teških neonatalnih oblika nerijetko postoji rezistencija na antihipoglikemike. Tada preostaje kirurško liječenje prije kojeg je potrebno odrediti histološki oblik bolesti, što se danas uspješno postiže kombinacijom genskog testiranja i scintigrafske pretrage. Kirurškim se zahvatom najčešće postiže izlječenje kod fokalnog KHI, dok difuzni oblik ima lošiju prognozu. Ovaj je tekst pregled novijih spoznaja o KHI, kojim želimo naglasiti važnost što ranijeg postavljanja dijagnoze kao preduvjeta uspješnoga ciljanog liječenja bolesti, koje je posljednjih godina obogaćeno novim mogućnostima., Congenital hyperinsulinism (CHI) is a major cause of persistent hypoglycemia in the neonatal and early infancy periods. Althought the disease is relatively rare with incidence of about 1: 25 000–50 000 live births, the importance of the disease should not be underestimated. Namely, prompt recognition and management of patients with CHI is essential, if permanent neurological impairment is to be avoided. CHI is caused by mutations in one of the 7 genes involved in the regulation of insulin secretion in pancreatic b-cells. It is important to introduce specific medical therapy as soon as diagnosis is established. Severe, neonatal forms of CHI are often resistant to medications, thus they require surgical procedure. The preoperative genetic testing and scintigraphy are indicated to distinguish histological subtypes of the disease (focal vs. diffuse CHI). Patients with focal disease are usually cured after pancreatic resection, while diffuse disease has much worse prognosis. This manuscript offers novel insights into CHI and emphasizes the role of early diagnosis as crucial for succesful treatment that was recently enriched with novel options.

Vitamin B12 (cobalamin) has two active forms, adenosylcobalamin and methylcobalamin which have a key role in two important metabolic pathways in humans and their deficiency is responsible for clinical problems. Cobalamin is essential during whole life, but its sufficient amount is extra important in fetal and neonatal period, when it is essential for normal child growth and development as well as for normal development of the central nervous system. Because of very complex transport and metabolism, its deficiency can be manifested in numerous congenital and acquired disorders. Vitamin B12 deficiency mostly has non-specific clinical features, it carries a great risk of permanent consequences, but most frequently it is easily curable if diagnosed on time. In Croatia cobalamin deficiency in children has been diagnosed too rarely. Accordingly, the aim of this paper is to point to the recently gained knowledge on cobalamin metabolism, present typical case reports and to provide guidelines for rapid and proper diagnostic and therapeutic approach.

Vitamin B12 (kobalamin) ima dva aktivna oblika, adenozilkobalamin i metilkobalamin, koji imaju ključnu ulogu u dvama važnim metaboličkim putovima u ljudi i njihov je manjak odgovoran za kliničke teškoće u bolesnika. Kobalamin je nuždan tijekom cijelog života, no njegova dovoljna količina posebno je bitna u fetalno i dojenačko doba, kada je iznimno važan za normalan rast i razvoj djeteta, kao i za normalan razvoj središnjega živčanog sustava. Zbog vrlo složenog prometa i metabolizma njegov se manjak može očitovati pri raznim prirođenim i stečenim poremećajima. Klinička slika kojom se očituje manjak vitamina B12 obično je nespecifična, nosi velik rizik od trajnih posljedica za bolesnika, a najčešće se vrlo jednostavno liječi ako se na vrijeme prepozna. U Republici Hrvatskoj poremećaji metabolizma kobalamina u djece prerijetko se otkrivaju. Zato je cilj ovog rada skrenuti pozornost na nove spoznaje o metabolizmu kobalamina, prikazati bolesnike s tipičnim kliničkim tijekom i laboratorijskim nalazima te dati smjernice za brzo dijagnosticiranje i liječenje poremećaja vitamina B12 u djece., Vitamin B12 (cobalamin) has two active forms, adenosylcobalamin and methylcobalamin which have a key role in two important metabolic pathways in humans and their deficiency is responsible for clinical problems. Cobalamin is essential during whole life, but its sufficient amount is extra important in fetal and neonatal period, when it is essential for normal child growth and development as well as for normal development of the central nervous system. Because of very complex transport and metabolism, its deficiency can be manifested in numerous congenital and acquired disorders. Vitamin B12 deficiency mostly has non-specific clinical features, it carries a great risk of permanent consequences, but most frequently it is easily curable if diagnosed on time. In Croatia cobalamin deficiency in children has been diagnosed too rarely. Accordingly, the aim of this paper is to point to the recently gained knowledge on cobalamin metabolism, present typical case reports and to provide guidelines for rapid and proper diagnostic and therapeutic approach.

Pallister Killian syndrome (PKS) is a rare genetic disorder caused by tetrasomy of the short arm of chromosome 12, revealed usually in mosaic distribution of an extra i(12)(p10) chromosome in fibroblasts. The syndrome presents with a recognizable pattern of findings including pigmentary skin changes, coarse face, high forehead, sparse anterior scalp hair, hypertelorism, seizures and progressive psychomotor developmental delay. It was first described independently by Pallister in 1977 and by Killian and Teschler-Nikola in 19811,2. We report a case of 21 month old girl with PKS and significant overgrowth. Cytogenetic analysis was performed using the GTG banding technique. The karyotype of cultured lymphocytes was normal. The karyotype from skin fibroblasts was established as mosaic tetrasomy of 12p 47,XX,+i(12) (p10)/46,XX. The origin of the extra marker chromosome was determinated by fluorescence in situ hybridization with chromosome 12 specific DNA probes confirming that supernumerary marker is chromosome i(12p) in 68% of cells. Despite the excessive postnatal growth we found low serum growth hormone levels and reduced response to pharmacological stimulation test. This is also the first report of a postnatal patient in our country.

Hypophosphatasia is a metabolic bone disease characterized by bone and teeth hypomineralization due to defective function of tissue-nonspecific alkaline phosphatase (TNSALP). The disorder is caused by various mutations in the TNSALP gene localized on short arm of chromosome 1. Infantile hypophosphatasia is a severe form of the disease inherited as an autosomal recessive trait which presents before age of six months and often has fatal outcome. We report a patient with typical clinical course for infantile hypophosphatasia who was homozygous for the c.1402G>A mutation. The same mutation has been previously associated with a more severe perinatal form also in a Croatian family what indicates a possible common ancestral origin and phenotypic variability potential of c.1402G>A mutation of TNSALP gene.

We have analyzed the morphology and den- dritic 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) ori- entation. A novel fi nding of this study is that members of the same population of pyramidal neurons display diff erent stages of development of their dendritic arborizations: some neurons had poorly developed dendrites and thus resem- bled pyramidal neurons of the late fetal cortex ; for some neurons, the level of diff erentiation cor- responded to that in the newborn cortex ; fi nally, 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 fi ndings suggest that Walker-Warburg lissencephaly is charac- terized by two hitherto unnoticed pathogenetic changes in the cerebral cortex: (a) heterochronic decoupling of dendritic maturation within the same neuronal population (with some members signifi cantly lagging behind the normal matura- tional schedule) and (b) anisotropically distorted shaping of dendritic trees, probably caused by patchy displacement of molecular guidance cues for dendrites in the malformed cortex.

Five children with adrenocorticotropic hormone (ACTH) insensitivity associated with autonomic nervous system disorders are described. A t the time of diagnosis, four of them had osteoporosis. The fifth p a t i e n t died and skeletal roentgenograms were n o t done. Osteoporosis was subsequently discovered in one of our previously rep o r t e d 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.

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.

Fumaric aciduria is a rare, autosomal recessive disorder caused by deficient acitivity of fumarate hydratase (FH), one of the constituent enzymes of the Krebs’ s cycle. The most common clinical features are hypotonia, failure to thrive, severe developmental retardation and seizures. Facial dysmorphy and brain malformations are frequent. We report a patient with relatively mild phenotype and previously not reported genotype.The patient is the only child of unrelated parents. Mother and grandmother had uterine myomas. The pregnancy was complicated by bleeding and intrauterine growth retardation. Delivery was spontaneous after 35 weeks, with normal Apgar ascore. The girl was hypotonic since birth. At age 2 months parents noticed short apnoic crises. Psychomotor delay became evident at age 6 months. At that time brain ultrasound revealed normotensive ventricular enlargement. She could sit at age 1.5 years, walk with assistance at 4 years. Diagnosis was established at age 8 years when 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, induced by various stimuli. She had grand mal seizures twice. Facial dysmorphy included depressed nasal bridge, otapostasis, hypertelorism and microcephaly. Speech was limited to few disyllable words. She was atactic with spastic paraparesis. Blood lactate was normal. Brain MRI showed slight ventriculomegaly, white matter atrophy and hypoplasia of corpus callosum. Acivity of FH in cultured skin fibroblasts was decreased to about 5% of the lowest value of 5 controls, i.e. to 1.9 nmol/min/mg protein (controls 40-80). The amount of FH was severely decreased, as well. Gene analysis revealed two mutations of the FH gene, the maternally derived [c. 1029_1031delAGT], resulting in Val deletion and amino acid substitution of Gln into His, and paternally derived [c. 976C>T], resulting in substitution of Pro into Ser.

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.

Glutaric aciduria type 1 (GA 1) is a preventable cause of acute brain damage in early childhood, leading to a severe dystonic-dyskinetic disorder. Typically between 6 and 18 months of age, a non-specific illness such as respiratory or gastrointestinal infection or immunization leads to encephalopathic crisis, usually resulting in degeneration of the putamen and caudate. GA 1 is an autosomal recessive disease of catabolism of amino acids lysine, hydroxylysine and tryptophane leading to accumulation of glutaric acid, 3-hydroxyglutaric acid and glutaconic acid. Recognition of this biochemical disorder before the brain has been injured is essential to the outcome. Diagnosis depends upon the recognition of relatively non-specific physical findings such as hypotonia, tremor, irritability and macrocephaly, and on urinary organic acids analysis. The diagnosis may also be suggested by characteristic findings of neuroimaging. Specific management includes pharmacological doses of 1-carnitine and dietary protein restriction. Metabolic decompensation must be treated vigorously to avoid permanent brain damage. With this case report the authors want to contribute to the early recognition of GA1, to the prevention of the related brain damage, and to increase awareness of the existence of so-called cerebral organic acidurias.

We report studies of a Croatian boy, a proven case of human S -adenosylhomocysteine (AdoHcy) hydrolase deficiency. Psychomotor development was slow until his fifth month; thereafter, virtually absent until treatment was started. He had marked hypotonia with elevated serum creatine kinase and transaminases, prolonged prothrombin time and low albumin. Electron microscopy of muscle showed numerous abnormal myelin figures; liver biopsy showed mild hepatitis with sparse rough endoplasmic reticulum. Brain MRI at 12.7 months revealed white matter atrophy and abnormally slow myelination. Hypermethioninemia was present in the initial metabolic study at age 8 months, and persisted (up to 784 μM) without tyrosine elevation. Plasma total homocysteine was very slightly elevated for an infant to 14.5–15.9 μM. In plasma, S -adenosylmethionine was 30-fold and AdoHcy 150-fold elevated. Activity of AdoHcy hydrolase was ≈3% of control in liver and was 5–10% of the control values in red blood cells and cultured fibroblasts. We found no evidence of a soluble inhibitor of the enzyme in extracts of the patient's cultured fibroblasts. Additional pretreatment abnormalities in plasma included low concentrations of phosphatidylcholine and choline, with elevations of guanidinoacetate, betaine, dimethylglycine, and cystathionine. Leukocyte DNA was hypermethylated. Gene analysis revealed two mutations in exon 4: a maternally derived stop codon, and a paternally derived missense mutation. We discuss reasons for biochemical abnormalities and pathophysiological aspects of AdoHcy hydrolase deficiency.

Short toddlers with bowed legs usually point to rickets as the probable diagnosis. Enlarged wrists and ankles support the impression and the demonstration of widened and irregular metaphyseal growth plates is consistent with that diagnosis. However, as in our patient, this is not always the case. A reliable history of preventive vitamin D3 intake should arouse suspicion of other forms of rickets such as X-linked hyp”phosphataemia, hypophosphataemia associated with primary or secondary Fanconi syndrome as seen in tyrosinaemia or cystinosis, or the rare "pseudodeficiency" rickets. The finding of normal calcium, phosphate and alkaline phosphatase should then direct the diagnosis towards *group of hereditary skeletal dysplasias, particularly to the metaphyseal dysplasias. Involvement limited to limbs (particularly legs) and to a much smaller extent to ribs, with spared epiphyses and spine, is typical for metaphyseal dysplasias. Normal hair, pancreatic function, immunological tests and absence of other skeletal abnormalities are not suggestive of several types of metaphyseal dysplasias (McKusick, Jansen, Schwachman-Diamond, other associated with immune defects) and make metaphyseal chondrodysplasia, Schmid type the most likely diagnosis. Enlarged femoral capital epiphyses can be seen in this skeletal dysplasia ). Progress in the molecular analysis of skeletal dysplasias allows a relatively easy, non-invasive and accurate diagnosis of many diseases within this group enabling more precise prognosis and genetic counselling. The diagnostic flowsheet of bowed legs and widened growth plates as outlined above suggested a provisional diagnosis of Schmid type metaphyseal chondrodysplasia relatively early and collagen 10 mutation analysis showed a hitherto unreported mutation which is analogous to previously observed ones and thus confirmed the diagnosis. Schmid type metaphyseal chondrodysplasia is inherited as an autosomal dominant trait, but de novo mutations, as in our patient, are not rare. The association between mutations in COLlOA1 (mapped to 6q21-q22.3)and Schmid type metaphyseal chondrodysplasia was first demonstrated by Warman et al. Subsequently, it was found that the great majority of such patients have mutations clustered in the carboxy-terminal region of the gene (5, 7, 8) and that other similar skeletal diseases are not caused by mutations in COLlOA1 8j. The exception was a mutation reccntly reported by Ikegawa et al. associated with metaphyseal dysplasia with spondylar involvement in a single Japanese patient. The expression of collagen 10 is restricted to the hypertrophic zone of the growth plate and this appears to be the explanation for the strictly metaphyseal pattern of Schmid type metaphyseal chondrodysplasia. While most forms of rickets, nutritional or secondary to genetic diseases, are amenable to medical treatment, Schmid type metaphyseal chondrodysplasia is not. Surgical correction of coxa vara and of genua vara is often indicated. Interestingly, during the periods of bed rest associated with medical treatment, the metaphyseal changes can temporarily disappear, indicating that the pathogenesis of the disorder involves mechanical weakness of the growth plates. Complications are unusual and adult height is usually around 140 to 150 cm.

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.

We present the results of a comprehensive analysis of mutations, polymorphisms and haplotypes in the phenylalanine hydroxylase (PAH) gene in 39 Croatian families with phenylketonuria (PKU). A total of 21 disease-causing mutations was identified on 78 out of 79 independent chromosomes. The commonest mutation, R408W on haplotype 2 was found with a relative frequency of 37 %. P281L accounted for 11 %, R261Q and E390G each for 9 % of mutant chromosomes. There were three novel mutations: L249P (c.746T>C) in exon 7, IVS8+2T>C (c.912T>C) in intron 8, and F402L (c.1206T>G) in exon 12 of the PAH gene. Two known PKU mutations were found in cis on the same chromosome in one family, highlighting the need to perform full mutation scanning in recessive disease genes for molecular diagnosis even if two known mutations have been identified in a patient. This is the first comprehensive report on PKU mutations in southeastern Europe, adding to the growing bulk of molecular data for population genetic investigations. © 2003 Wiley-Liss, Inc.