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The finding of individuals homozygous for FAP I (familial amyloidotic polyneuropathy, transthyretin TTRMet30) with amyloid deposits in the vitreous body, gave us access to a unique material lacking wild type transthyretin and contaminating proteins. Amyloid TTR is modified in several ways. Besides the full-length protein and its dimer form, two smaller bands were identified by SDS-PAGE and protein sequencing. One corresponded to a peptide starting at amino acid Thr49, the other was a mixture of two peptides starting at positions 1 and 3 in a 3:1 ratio. Upon reduction the amount of the TTR dimer decreased, the monomer amount increased, and the resulting monomers became available for carboxymethylation. Moreover, the mobility of the small band, which includes Cys10, increased upon reduction. This cysteine seemed to be involved in an interchain disulfide bridge both between intact TTR molecules and between small fragments. The same pattern was found in heterozygous fibril material although smaller amounts of the truncated peptides were found. Fibrils were formed both from normal and mutated TTR in heterozygotes. The significance of our results for amyloid formation is discussed.

The structure of a variant transthyretin has been determined by X-ray crystallography at 2.3 A resolution in order to investigate those changes which lead to amyloid formation. This variant transthyretin, in which the internal valyl residue at position 30 is replaced by methionyl, is associated with the most common form of familial amyloidotic polyneuropathy (FAP). Comparison to the known structure of the normal transthyretin tetramer shows that the bulkier methionine residue 30 which lies between the nearly orthogonal beta sheets of the dimer, results in the sheets being displaced an average of 0.4 A. The internal structure of the sheets and of the monomer-monomer interface is maintained. Such global changes may affect the metabolic properties and the tendency towards polymerization of the mutant protein. These findings may form a basis for understanding other amyloid-deposition diseases.

Chromosomes carrying the mutation causing the fragile X [fra(X)] syndrome have been shown to have an unstable DNA sequence close to or within the fragile site. The length variation is located within a DNA fragment containing a CGG trinucleotide repeat which is unstable in both mitosis and meiosis. We have used the probe StB12.3 from the region to analyze the mutations and the methylation patterns in 21 families segregating for the fra(X) syndrome. Among 40 fra(X) males all showed an abnormal pattern. The normal 2.8 kb band was absent in 36 individuals and replaced by a heterogeneous smear of larger size. The remaining four were shown to be "mosaics" with the presence of both mutated, unmethylated and mutated, methylated fragments. We found four normal transmitting males, one which was a great-grandson of another normal transmitting male indicating that the pre-mutation can remain stable through two meioses in the female. In nine fra(X) positive females the abnormal pattern consisted of a smear, usually seen in affected males, in addition to the normal bands. Five of these females were mentally normal. Of clinical importance is the prediction of mental impairment in females. We suggest that this is not made by the detection of the full mutation alone, but rather by the degree of methylation of the normal X chromosome. Our results suggest that difference of clinical expression in monozygotic twins may be correlated with difference in methylation pattern. Six out of 33 fra(X) negative females at risk were diagnosed as carriers. Our observations indicate that molecular heterogeneity is responsible for variable expression of the fra(X) syndrome in both males and females.

Finnish hereditary amyloidosis-Meretoja (FAP type 4) is the predominating type of hereditary amyloidosis in the Finnish population, found in more than 200 individuals. We present a Finnish family with familial amyloidotic polyneuropathy (FAP Met30), a type of amyloidosis hitherto not described in the Finnish population. Genealogical tracing back to the 18th century revealed no connections with Swedish FAP families, but introduction from Sweden is the most probable origin of the FAP Met30 gene.

We report on 4 individuals with the fragile X [fra(X)] syndrome and the Robin sequence (or elements of that sequence). To our knowledge, this association has been described in only one other boy. However, males with the fra(X) syndrome have been reported to have an increased incidence of cleft palate. We recommend that children with a cleft palate or the Robin sequence be assessed for developmental delays and a family history of mental retardation. The fra(X) syndrome may be one of the genetic causes of the Robin sequence and, when indicated, children with the sequence should be tested for fra(X).

Alcohol-responsive myoclonic dystonia is reported in 26 individuals in a six-generation family, thus indicating autosomal dominant inheritance. Twenty affected family members aged between 3 and 56 years were examined on one occasion. Myoclonus in arms, shoulder, and neck distribution was seen in 17, with occasional generalized jerks in 14. Leg dystonia/hemidystonia was seen in two infant cases, writer's cramp in seven, torticollis/retrocollis in two, and finger tremor in three. The onset of myoclonus was regularly reported from 2 to 3 years of age, the onset of leg dystonia/hemidystonia from 6 to 18 months of age, writer's cramp from early school age, and neck dystonia from late teenage. The effect of alcohol had been noted in 10 individuals, and seven of them abused alcohol. Once established, the neurological signs did not progress significantly. Leg dystonia resolved in two juvenile members. Two adult members had recovered from myoclonus: one elderly man and one posthemorrhagic spastic hemiplegic man. Extensive family investigation is necessary to clarify the clinical variation of this autosomal dominant disorder of involuntary movements.

Sjogren Larsson syndrome (SLS) is a rare, autosomal recessive disorder characterized by congenital ichthyosis, mental retardation, and spastic diplegia or tetraplegia. The disorder has the highest incidence in the north of Sweden and most of the cases are caused by a C943T mutation in the FALDH gene. Prenatal diagnosis and PCR-based mutation analysis was performed in a pregnancy where the parents are heterozygous carriers for this mutation. The fetus was found to be homozygous for the mutation and thus affected by SLS.

We report two new amyloidogenic transthyretin (TTR) variants detected in the Swedish population. One variant was previously unknown, while the other has been described in a French family. In Swedish patients, both variants have caused late-onset cardiac amyloidosis characterised by heart failure. In both cases, the diagnosis was determined by the detection of amyloid deposits in skin and/or rectal biopsies and identification of TTR mutations by genetic analysis. The index case of the previously unknown mutation (ATTR His88Arg) was a 66-year-old Swedish man, who sought medical attention for increasing dyspnea. Echocardiographic examination disclosed a restrictive cardiomyopathy, and subsequent examinations disclosed TTR amyloidosis. The patient is alive with moderate symptoms one year after the onset of disease. The index case for the new Swedish mutation (ATTR Gly53Glu) is a woman who sought medical attention at the age of 57 because of increasing dyspnea. Echocardiographic examination disclosed a hypertrophic cardiomyopathy with diastolic impairment. The diagnosis of systemic amyloidosis was made by fat aspiration biopsy and histopathology. The patient developed severe intractable heart failure, with pulmonary effusion and ascites. She died four years after the onset of her disease of intractable heart and kidney failure. Post mortem examination of biopsy specimens and blood revealed TTR amyloid deposits and the ATTR Gly53Glu mutation was detected.

Senile systemic amyloidosis (SSA) results from deposition, predominantly in the heart, of amyloid fibrils derived from wild-type transthyretin (T TR) molecules. Cardiac autopsies indicate that SSA progressively increases in subjects 80 years of age and older. However, only a few cases of patients with SSA and cardiac failure have been recognized by cardiac biopsies during life. Here, we report a case of heart transplantation in a 68-year-old male patient with SSA. After cardiopulmonary resuscitation in October 1998, he underwent complete evaluation. Myocardial biopsies revealed the presence of amyloid deposition. Immunohistochemical staining of the amyloid indicated T TR. Genomic DNA analysis of the T TR exons did not result in any identification of a mutation. In 2001, heart transplantation was performed because progressive heart failure occurred. At the 1-year follow-up, no amyloid deposits were found in the donor heart. At the 2-year follow-up, the patient's physical and mental health was excellent. We conclude that heart transplantation can be an effective treatment in progressive heart failure due to SSA.

Over fifty transthyretin variants have been described, mostly in patients with familial amyloidoses (familial amyloidotic-polyneuropathy (FAP) and familial amyloidotic cardiomyopathy (FAC)). Other TTR variants, including TTR Ser6, have been found in screening studies of the “normal” population and, apparently, are non-pathogenic.The role of TTR mutations in amyloid formation is not yet fully understood and it is relevant to study individuals carrying two TTR variants, to examine the possible inter-action of such variants in amyloidogenesis.We previously reported that TTR Ser6 is a common polymorphism. To investigate whether this variant might have an effect on TTR amyloidogenicity and clinical disease expression, we have screened for TTR Ser6 in 85 patients carriers of TTR Met30 and 12 patients with senile systemic amyloidosis (SSA). Among the FAP patients, seven were found to be compound heterozygotes carrying also Ser6 on the other allele. No Ser6 allele was found in individuals with systemic senile amy...

Familial amyloidotic polyneuropathy is the common form of hereditary generalized amyloidosis and is characterized by the accumulation of amyloid fibrils in the peripheral nerves and other organs. Liver transplantation (LTx) has been utilized as a therapy for familial amyloidotic polyneuropathy because the variant transthyretin (TTR) is predominantly synthesized by the liver, but this therapy has several problems. Thus, we need to develop a new treatment that prevents the production of the variant TTR in the liver. In this study, we used HepG2 cells to show in vitro conversion of the TTR gene by single-stranded oligonucleotides, embedded in atelocollagen, designed to promote endogenous repair of genomic deoxyribonucleic acid. For the in vivo portion of the study, we used liver from transgenic mice whose intrinsic wild-type TTR gene was replaced by the murine TTR Val30Met gene. The level of gene conversion was determined by real-time RCR combined with mutant-allele-specific amplification. Our results indicated that the level of gene conversion was approximately 11 and 9% of the total TTR gene in HepG2 cells and liver from transgenic mice, respectively. In conclusion, gene therapy via this method may therefore be a promising alternative to LTx for treatment of familial amyloidotic polyneuropathy. (Gene Ther 2004;11:838–846.)

Familial amyloidotic polyneuropathy (FAP) is caused by mutated transthyretin in which valine at position 30 is substituted by methionine (ATTR Val30Met). FAP is inherited as an autosomal dominant trait with variable penetrance.Two pairs of DNA confirmed monozygotic twin brothers, 63 and 37 years of age respectively, who are heterozygous for the ATTR Val30Met gene, have been identified in Sweden. In the first twin pair (A), the onset of typical FAP symptoms occurred at the age of 48 for twin A1, whilst his twin brother (A2) is still free from FAP symptoms 13 years later. In the second pair of twins (B), the onset of polyneuropathy occurred at the age of 34 for the proband (B1), whilst his brother (B2) is healthy 3 years after the onset of his brother's disease.In the following, a detailed description of the clinical presentation of the Swedish twin pairs is provided together with a discussion of possible environmental factors initiating the onset of the disease.

Between 1993 and 2001, 318 children were diagnosed with acute myeloid leukaemia (AML) in the Nordic countries. The patient group comprised 237 children15 years of age with de novo AML, 42 children15 years with Down syndrome (DS) and de novo AML, 18 adolescents 15-18 years of age with de novo AML, and 21 children15 years with treatment-related AML (t-AML). The first group was all-inclusive, yielding an annual childhood de novo AML incidence of 0.7/100 000. Cytogenetic analyses were successful in 288 cases (91%), and clonal chromosomal abnormalities were detected in 211 (73%). The distribution of ploidy levels were pseudodiploidy (55%), hyperdiploidy (34%) and hypodiploidy (11%). The most common aberrations (2%) were + 8 (23%) (as a sole change in 6.2%), 11q23-translocations, including cryptic MLL rearrangements (22%) [t(9;11)(p21-22;q23) in 11%], t(8;21)(q22;q22) (9.0%), inv(16)(p13q22) (6.2%), -7/7q- (5.2%), and t(15;17)(q22;q12) (3.8%). Except for +8, these abnormalities were rare in group 2; only one DS patient had a t(8;21) and none had 11q23-translocations, t(15;17) or inv(16). In the t-AML group, three cases displayed 11q23-rearrangements, all t(9;11); and there were no t(8;21), t(15;17) or inv(16). Overall, the observed frequencies of t(8;21) and t(15;17) were lower, and frequencies of trisomy 8 and 11q23-translocations higher, than in previous studies. Furthermore, seven abnormalities that were previously reported as only single AML cases were also seen, meaning that der(4)t(4;11)(q26-27;q23), der(6)t(1;6)(q24-25;q27), der(7)t(7;11)(p22;q13), inv(8)(p23q11-12), t(11;17)(p15;q21), der(16)t(10;16)(q22;p13) and der(22)t(1;22)(q21;q13) are now classified as recurrent abnormalities in AML. In addition, 37 novel aberrations were observed, 11 of which were sole anomalies.

Mutations in the human cellular retinaldehyde binding protein (CRALBP) gene cause retinal pathology. To understand the molecular basis of impaired CRALBP function, we have characterized human recombinant CRALBP containing the disease causing mutations R233W or M225K. Protein structures were verified by amino acid analysis and mass spectrometry, retinoid binding properties were evaluated by UV-visible and fluorescence spectroscopy and substrate carrier functions were assayed for recombinant 11-cis-retinol dehydrogenase (rRDH5). The M225K mutant was less soluble than the R233W mutant and lacked retinoid binding capability and substrate carrier function. In contrast, the R233W mutant exhibited solubility comparable to wild type rCRALBP and bound stoichiometric amounts of 11-cis- and 9-cis-retinal with at least 2-fold higher affinity than wild type rCRALBP. Holo-R233W significantly decreased the apparent affinity of rRDH5 for 11-cis-retinoid relative to wild type rCRALBP. Analyses by heteronuclear single quantum correlation NMR demonstrated that the R233W protein exhibits a different conformation than wild type rCRALBP, including a different retinoid-binding pocket conformation. The R233W mutant also undergoes less extensive structural changes upon photoisomerization of bound ligand, suggesting a more constrained structure than that of the wild type protein. Overall, the results show that the M225K mutation abolishes and the R233W mutation tightens retinoid binding and both impair CRALBP function in the visual cycle as an 11-cis-retinol acceptor and as a substrate carrier.

A small rural district in the most northerly province of Sweden was found to have a very high occurrence of multiple sclerosis. A total of 12 patients with multiple sclerosis among 4744 inhabitants were identified (five females, seven males), corresponding to a prevalence of 253/100,000. Many of the patients were related and a further 21 cases with multiple sclerosis (14 females, seven males), mostly living in the neighbouring area, have family ties to the district. A genealogical investigation showed that 22 of the 33 patients identified had ties of kinship and thus, to our knowledge, the largest aggregation of multiple sclerosis in a family is presented.

Amelogenesis imperfecta (AI) is an inherited tooth disorder affecting tooth enamel formation only. A gene for autosomal dominant AI, the local hypoplastic form, has been localized to a 4 Mb region on chromosome 4q (AIH2). The enamelin gene (ENAM ), has been mapped to chromosome 4q21, to the same region as AIH2, and was recently shown to be mutated in patients with smooth and thin hypoplastic autosomal dominant AI (ADAI). In this study, we describe an ENAM mutation causing the local hypoplastic form of ADAI, a phenotype that accounts for 27% of the autosomally inherited cases in Northern Sweden. This nonsense mutation in the enamelin gene results in a truncated peptide of 52 amino acids as compared with 1142 amino acids of the normal protein. Our results show that while a splice site mutation is associated with smooth and thin hypoplastic AI, a base substitution resulting in a shorter peptide causes local hypoplasia of the enamel, a milder form of AI. These findings support ENAM as a disease gene, and shed new light on the molecular mechanism of the disease and to the function of the enamelin protein in enamel formation.

Myotonia congenita is a non-dystrophic muscle disorder affecting the excitability of the skeletal muscle membrane. It can be inherited either as an autosomal dominant (Thomsen's myotonia) or an autosomal recessive (Becker's myotonia) trait. Both types are characterised by myotonia (muscle stiffness) and muscular hypertrophy, and are caused by mutations in the muscle chloride channel gene, CLCN1. At least 50 different CLCN1 mutations have been described worldwide, but in many studies only about half of the patients showed mutations in CLCN1. Limitations in the mutation detection methods and genetic heterogeneity might be explanations. In the current study, we sequenced the entire CLCN1 gene in 15 Northern Norwegian and three Northern Swedish MC families. Our data show a high prevalence of myotonia congenita in Northern Norway similar to Northern Finland, but with a much higher degree of mutation heterogeneity. In total, eight different mutations and three polymorphisms (T87T, D718D, and P727L) were detected. Three mutations (F287S, A331T, and 2284+5C>T) were novel while the others (IVS1+3A>T, 979G>A, F413C, A531V, and R894X) have been reported previously. The mutations F413C, A531V, and R894X predominated in our patient material. Compound heterozygosity for A531V/R894X was the predominant genotype. In two probands, three mutations cosegregated with myotonia. No CLCN1 mutations were identified in two families. Our data support the presence of genetic heterogeneity and additional modifying factors in myotonia congenita.

Since oxidative stress has been implicated in amyloid diseases, a study of scavenger treatment of hereditary transthyretin amyloidosis was undertaken on 23 familial amyloidotic polyneuropathy (FAP) patients. Nine patients had undergone a liver transplantation for the disease. Twenty patients completed the 6-month study period of scavenger treatment (vitamin C, 1 g, three times daily, vitamin E, 0.1 g, three times daily and acetylcysteine, 0.2 g three times daily). They were evaluated clinically and by immunohistochemical measurement of hydroxynonenal (HNE), a product of lipid peroxidation, in biopsy specimens. For non-transplanted patients, no improvement was found for HNE in relation to the amyloid content in biopsy specimens, whereas a tendency to a decreased amount was noted for transplanted patients. Clinically, no differences were found for non-transplanted patients, but an increased nutritional status, measured by a modified body mass index (mBMI) was noted for transplanted patients. In summary, scavenger treatment with the drugs and doses used in the present study appears to be unable to decrease lipid peroxidation in amyloid-rich tissue in non-transplanted FAP patients. For transplanted patients, lipid peroxidation tended to decrease, and the nutritional status measured by mBMI improved, even though the findings may be explained by liver transplantation alone, scavenger treatment may facilitate recovery after transplantation.

Spinocerebellar ataxia type 7 (SCA7) is a neuro-degenerative disorder characterised by progressive cerebellar ataxia and macular degeneration. SCA7 is one of the least common genetically verified autosomal dominant cerebellar ataxias (ADCAs) in the world (4.5 to 11.6%), but in Sweden and Finland SCA7 is the most commonly identified form of ADCA. In an inventory of hereditary ataxias in Scandinavia (Sweden, Norway, Denmark and Finland) we identified 15 SCA7 families, eight in Sweden and seven in Finland, while no cases of SCA7 could be found in Norway or Denmark. We examined whether the relatively high frequency of SCA7 families in Sweden and Finland was the result of a common founder effect. Only two out of 15 families could be connected genealogically. However, an extensive haplotype analysis over a 10.2 cM region surrounding the SCA7 gene locus showed that all 15 families studied shared a common haplotype over at least 1.9 cM. This strongly suggests that all Scandinavian SCA7 families originate from a common founder pre-mutation.

We present the clinical and molecular genetic features of a large multi-generation Norwegian family with dominant cone-rod dystrophy. Ophthalmological evaluation including electroretinography showed cone dysfunction in younger patients, with rod dysfunction becoming apparent at more advanced stages of the disease. In one branch of the family, cone degeneration remained the only manifestation despite advancing age. Linkage analysis mapped the disease gene in this family to 17p12-p13, a chromosome region previously linked to cone-rod dystrophy in a Swedish family (CORD5). A maximum LOD score of 3.25 (straight theta = 0.00) for marker D17S1844 was obtained. Mutation analysis of the guanylate cyclase 2D gene (GUCY2D, MIM 600179, previously called RETGC1), located at 17p12-p13, showed a missense mutation (R838C) in exon 13, that co-segregated with the eye disease in the family. Our suspicion of the possibility of an interrelationship between the Swedish CORD5 family and the present family, both originating from Northern Scandinavia, initiated the linkage analysis in the Norwegian family. The R838C missense mutation was not, however, detected in the Swedish patients, strongly suggesting no relationship between these two families. The long-term ophthalmological evaluation in this large four-generation family, combined with the identification of the disease-causing mutation, provide critical information for refining the classification, prognosis, and genetic counselling of patients with cone-rod dystrophies.

Myoclonus-dystonia (M-D) is an autosomal dominant disorder characterized by myoclonic and dystonic muscle contractions that are often responsive to alcohol. The dopamine D2 receptor gene (DRD2) on chromosome 11q has been implicated in one family with this syndrome, and linkage to a 28-cM region on 7q has been reported in another. We performed genetic studies, using eight additional families with M-D, to assess these two loci. No evidence for linkage was found for 11q markers. However, all eight of these families showed linkage to chromosome 7 markers, with a combined multipoint LOD score of 11.71. Recombination events in the families define the disease gene within a 14-cM interval flanked by D7S2212 and D7S821. These data provide evidence for a major locus for M-D on chromosome 7q21.

Cardiac failure in transthyretin (TTR) amyloidosis patients has been shown to be caused by different mutations in the TTR gene. In the present case, a 73-year-old man from Northern Sweden was evaluated for heart failure. Amyloid deposits were found in subcutaneous fat and in intestinal biopsies. The presence of a variant form of TTR was detected in the plasma by electrospray ionisation mass spectrometry (ESI-MS). The mutation was located by single-strand conformation polymorphism (SSCP) analysis of the TTR gene where a band shift was seen in exon 2. Direct sequencing of exon 2 revealed a single base-pair substitution (G1724T). This transversion results in an amino acid substitution at codon 45, alanine to serine (ATTR Ala45Ser). Mass spectrometry analysis excluded that the variant is a polymorphism, since no similar shift in molecular weight has been present in more than 200 control samples. Congo red and immunostaining of duodenum biopsy specimens confirmed the presence of systemic ATTR amyloidosis, and clinical examination, including echocardiography, found evidence of a restrictive cardiomyopathy. He had 10 years previously been operated for a bilateral carpal tunnel syndrome, but otherwise no symptoms were present that could be attributed to his systemic amyloidosis. No axonal polyneuropathy was noted at nerve conduction studies. This novel mutation is the second amyloidogenic TTR mutation found in the Swedish population.

The mechanism behind amyloid formation is unknown in all types of amyloidosis. Several substances can enhance amyloid formation in animal experiments. To induce secondary systemic amyloid (AA-type amyloid) formation, we injected silver nitrate into mice together with either amyloid fibrils obtained from patients with familial polyneuropathy (FAP) type I or polyethylene glycol (PEG). Mice injected with silver nitrate only served as controls. Amyloid deposits were detectable at day 3 in animals injected with amyloid fibrils and in those injected with PEG, whereas in control mice, deposits were not noted before day 12. Our results indicate that amyloid fibrils from FAP patients and even a non-sulfate containing polysaccharide (PEG) have the potential to act as amyloid-enhancing factors.

Congenital dyserythropoietic anaemia type III (CDA III) is a rare disease inherited in an autosomal dominant way and characterized by mild to moderate haemolytic anaemia. Most patients are adapted to their disease and have no or few complaints. Bone marrow examination shows a characteristic picture with erythroid hyperplasia and multinucleate erythroblasts. 20% of patients in a Swedish family affected with the CDA III condition have monoclonal gammopathy or multiple myeloma. By linkage and recombination analysis in the same family, the gene linked to the CDA III condition (CDAN3) has been located to chromosome 15q22. In this paper we report the observation of visual disturbances with macular degeneration and angioid streaks in six patients with CDA III and discuss the apparent association between CDA III, angioid streaks and monoclonal gammopathy. We suggest that this triad forms a previously unreported syndrome.

Oxidative stress in human amyloid deposits from patients with systemic amyloidosis, such as familial amyloidotic polyneuropathy (FAP), primary amyloidosis, and secondary amyloidosis, was examined immunohistochemically by means of an affinity purified anti-hydroxynonenal (HNE) antibody to HNE, a marker of lipid peroxidation. Furthermore, the levels of thiobarbituric acid reactive substances (TBARS), which is another marker of lipid peroxidation, and the levels of protein carbonyl, a maker of protein modifications by free radicals, were determined in FAP patients and healthy controls. Affinity purified anti-HNE antibody reacted with amyloid deposits in all types of amyloid tissues examined. Significantly higher levels of TBARS and protein carbonyl were found in amyloid rich tissues of FAP patients compared with those in the control subjects. These results verify that lipid peroxidation via free radical injury occurs in amyloid deposits in systemic amyloidosis. The protein modifying properties of free radicals increase the likelihood that they play an important role in the amyloid formation process.

The autosomal dominant cerebellar ataxias (ADCA) are a group of neurodegenerative disorders with ataxia and dysarthria as early and dominant signs. In ADCA type II, retinal degeneration causes severe visual impairment. ADCA type II has recently been mapped to chromosome 3p by three independent groups. In the family with ADCA type II studied here, the disease has been mapped to chromosome 3p12-p21.1. Histochemical examination of muscle biopsies in 5 cases showed slight neurogenic atrophy and irregular lobulated appearance or focal decreases of enzyme activity when staining for NADH dehydrogenase, succinic dehydrogenase and cytochrome oxidase. Ragged-red fibres were scarce. Electron microscopic examination showed uneven distribution of mitochondria with large fibre areas devoid of mitochondria and/or large subsarcolemmal accumulations of small rounded mitochondria, and frequent autophagic vacuoles. These vacuoles contained remnants of multiple small rounded organelles, possibly mitochondria, and had a remarkably consistent ultrastructural appearance. Biochemical investigation of mitochondrial function showed reduced activity of complex IV and slightly reduced activity of complex I in the respiratory chain in a severely affected child while no abnormalities were found in his affected uncle.

We report two brothers with glycerol kinase deficiency (GKD). The older brother had serious clinical symptoms, mental and growth retardation, abnormal skeleton, spontaneous fractures and premature loss of abnormal teeth. He and his mother had low serum phosphate levels. He had elevated serum and urine glycerol levels and GKD was found in cultured fibroblasts. Prenatal diagnosis was performed in the second pregnancy. Glycerol kinase activity was considered normal in a chorionic villus sample of the foetus. After birth, it was found that the boy had elevated serum and urine glycerol levels. Enzymatic analysis in cultured fibroblasts revealed that this boy also had GKD, in spite of having no expression of the disease. Chromosomal analyses in the parents and both boys were normal. Major rearrangements or deletions were not detected in molecular studies of DNA from the two brothers. The hybridisation pattern was normal and no allelic loss was observed.

International audience; Expanded CAG repeat sequences have been identified in the coding region of genes mutated in several neurodegenerative disorders, including spinocerebellar ataxia type 1 and Machado-Joseph disease. In all disorders described to date the CAG expansion codes for an elongated polyglutamine chain. An increased polyglutamine chain size leads to a more severe disease, thus correlating with the genetic anticipation seen in repeat expansion disorders. Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant spinocerebellar ataxia with anticipation and a progressive degeneration of the cerebellar cortex. Using repeat expansion detection (RED), a method in which a thermostable ligase is used to detect repeat expansions directly from genomic DNA, we have analyzed 8 SCA7 families for the presence of CAG repeat expansions. RED products of 150-240 bp were found in all affected individuals and found to cosegregate with the disease (P < 0.000001, n = 66), indicating strongly that a CAG expansion is the cause of SCA7. On the basis of a previously established correlation between RED product sizes and actual repeat sizes in Machado-Joseph disease, we were able to estimate the average expansion size in SCA7 to be 64 CAG copies.

Inherited retinal dystrophy is a common cause of visual impairment. Cone dystrophy affects the cone function and is manifested as progressive loss of the central vision, defective color vision, and photophobia. Linkage was demonstrated between progressive cone dystrophy (CORD5) and genetic markers on chromosome 17p12-p13 in a five-generation family. Multipoint analysis gave a maximum lod score of 7.72 at the marker D17S938. Recombinant haplotypes in the family suggest that the cone dystrophy locus is located in a 25-cM interval between the markers D17S926/D17S849 and D17S804/D17S945. Furthermore, one recombination was detected between the disease locus and a microsatellite marker in the candidate gene RCV1, encoding the retinal protein recoverin. Two additional candidate genes encoding retinal guanylate cyclase (GUC2D) and pigment epithelium-derived factor (PEDF) are located at 17p13.1. Moreover, loci for retinitis pigmentosa and Leber congenital amaurosis have been mapped to the same region. Identification of the cone dystrophy locus may be of importance not only for identifying functional genes in the cone system, but also for identifying genes for other retinal disorders.

The most frequent transthyretin (TTR) variant associated with hereditary amyloidosis is TTR Met 30, which has its major focus in Portugal, although it also occurs in many other countries. The distribution of the mutation and its occurrence in a CpG dinucleotide lead us to question the origin of the mutation and the possibility of its having originated in Portugal. In order to investigate these questions, we studied the distribution of haplotypes associated with the Met 30 mutation in families from different European countries. All the analysed Portuguese families presented the same haplotype associated with the Met 30 mutation (haplotype I). The same was found for the Swedish and Spanish families studied. However, a distinct haplotype (haplotype III) was found in three families, one Italian, one English and one Turkish. These results suggest that, although the Portuguese Met 30 carriers might have one founder, the mutation probably recurred in populations in Europe in a similar manner to that reported in Japan. In this study, we have also analysed the haplotypes associated with other TTR variants frequent in the Portuguese population.

We present linkage analysis on a large Swedish five-generation family of 15 affected individuals with autosomal dominant cerebellar ataxia (ADCA) associated with retinal degeneration and anticipation. Common clinical signs in this family include ataxia, dysarthria and severely impaired vision with the phenotype ADCA type II. Different subtypes of ADCA have proven difficult to classify clinically due to extensive phenotypic variability within and between families. Genetic analysis of a number of ADCA type I families shows that heterogeneity exists also genetically. During the last few years several types of ADCA type I have been localized and to date six genetically distinct forms have been identified including SCA1 (6p), SCA2 (12q), SCA3 and Machado-Joseph disease (MJD) (14q), SCA4 (16q), and finally SCA5 (11). We performed a genome-wide search of the Swedish ADCA type II family using a total of 270 microsatellite markers. Positive lod scores were obtained with a number of microsatellite markers located on chromosome 3p12-p21.1. Three markers gave lod scores over 3 with a maximum lod score of 4.53 achieved with the marker D3S1600. The ADCA type II gene could be restricted to a region of 32 cM by the markers D3S1547 and D3S1274.

The Best`s macular dystrophy (BMD) gene has previously been mapped to the 11q13 region. In this study, recombination data localizes the BMD gene to the 6-cM genetic interval between the markers Fc{epsilon}RI and D11S480/ROM1 in a large Swedish 12-generation BMD family. Mutation analyses of the candidate gene ROM1 did not reveal any mutations that could explain the disease phenotype. However, one recombination event between intragenic ROM1 polymorphisms and the BMD phenotype was detected. Therefore, it is highly unlikely that mutations in the ROM1 gene cause BMD. Identification of the disease gene will elucidate the pathophysiological mechanism in BMD, which may also be of importance in other retinopathies such as age-related macular degeneration. 50 refs., 4 figs., 4 tabs.

Hereditary palmoplantar keratoderma is characterized by hyperkeratosis of the skin of palms and soles. An autosomal dominant form of diffuse non-epidermolytic palmoplantar keratoderma, frequently complicated by fungal infections, is encountered in northern Sweden with a prevalence of 0.3-0.55%. We have examined two families with this type of palmoplantar keratoderma and localized the causative genetic defect to a 14 cM interval on chromosome 12q11-q13, a region known to contain the keratin type II gene cluster as well as the retinoic acid receptor gamma gene. The palmoplantar keratoderma variant investigated in this study is thus genetically different from epidermolytic palmoplantar keratoderma, which recently has been shown to result from mutations in the gene for the type I keratin 9.

The first Swedish case of familial amyloidotic polyneuropathy (FAP) was published in 1965. The same transthyretin (TTR met30) mutation as that seen in Japanese, Portuguese, and other populations was also found in Swedish FAP patients. More than 350 patients with clinical manifestations of FAP have been diagnosed in northern Sweden, most of them originating from the areas around Skelleftea and Pitea. The mean age of onset is 56 years, much later than in patients from Japan and Portugal. To estimate the frequency of the TTR met30 mutation in the counties of Vasterbotten and Norrbotten, sera from 1276 persons aged 24 to 65 years, randomly sampled from a health programme (MONICA), were screened with the monoclonal antibody FD6. In 19 persons, 13 females and six males, a positive reaction was seen in an Elisa test using this antibody. DNA analysis confirmed the TTR met30 mutation and showed that 18 were heterozygous and one homozygous for this mutation. Other mutations were not looked for in this study. The mean TTR met30 carrier frequency in the area was 1.5% ranging from 0.0 to 8.3% in 23 subpopulations. There was a notable discrepancy between the regional distribution of the TTR met30 allele and the morbidity rate for FAP. The estimated number of TTR met30 gene carriers in a total population of 500,000 in the area is approximately 7500. The penetrance of the TTR met30 mutation shows considerable variation between families, and the overall diagnostic (predictive) value in this population is as low as around 2%.

Objectives. To describe the evolution of nutritional and neurological complications in a Swedish population of patients with familial amyloidotic polyneuropathy, and to identify prognostic factors and useful tests for monitoring the progress of the disease. Design. Prospective and retrospective study of patients with familial amyloidotic polyneuropathy. Setting. Tertiary referral centre. Subjects. Twenty-seven patients with familial amyloidotic polyneuropathy, and a symptomatic onset before the age of 50. Main outcome measures. Age at onset, duration of disease before death, serum albumin, body mass index (BMI), duration and grade of peripheral neuropathy and gastrointestinal disturbances. Faecal fat, xylose test and 75selenohomocholic acid-taurine (SeHCAT) test were used for assessment of malabsorption. Results. Thirteen patients died during the study period after a disease duration of between 9 and 18 years (mean 13). A short time interval between the onset of neurological and of gastrointestinal symptoms had greater impact on survival than age at onset in this selected group of patients (r = 0.65; P = 0.017). Malnutrition was evaluated by multiplying the [body weight (kg)/height2 (m)] with the serum albumin to compensate for oedema. This modified body mass index (mBMI) was significantly correlated to the number of years before death (r = 0.89; P < 0.0005) and to the duration of gastrointestinal symptoms (r = —0.66; P < 0.0005), but not to duration of disease (r = —0.2; P = 0.20). Polyneuropathy was graded according to functional capacity from I to IV (PND score) and was correlated to the number of years before death and mBMI, but not to serum albumin. The SeHCAT test for bile acid malabsorption was significantly correlated to the duration of gastrointestinal symptoms and to mBMI (r = —0.67; P = 0.0003 and r = —0.62; P = 0.003, respectively). Conclusion. The investigation disclosed that a short time interval between the onset of neurological and of gastrointestinal symptoms is associated with a decreased survival time. The mBMI was closely related to time before death, duration of gastrointestinal disturbances, malabsorption and functional capacity. The mBMI appears to be well suited to monitoring disease progress and gives prognostic information.

Sixty-seven patients in 29 families with the diagnosis of Charcot-Marie-Tooth disease or hereditary motor and sensory neuropathy in northern Sweden were examined by pedigree and DNA analysis for the CMT1a duplication within chromosome 17p11.2. There were 39 patients in nine families with Charcot-Marie-Tooth type 1 and autosomal dominant inheritance and in all these cases the duplication was seen. In six patients in three families with Charcot-Marie-Tooth type 1 the pedigrees strongly suggested autosomal recessive inheritance. In two patients DNA analysis was not informative but in the others no duplication was shown. There were also 11 "sporadic" patients and one pair of sibs classified as Charcot-Marie-Tooth type 1, but there was no duplication shown although in four patients DNA analysis was not informative. In nine patients with Charcot-Marie-Tooth type 2 from five families and in 13 unaffected relatives of Charcot-Marie-Tooth patients the CMT1a duplication was not found.

We analyzed the FRAXAC2 and DXS548 microsatellites in normal and fragile X chromosomes from Sweden and the Czech Republic in order to investigate a possible founder effect for chromosomes carrying a fragile X mutation. We report a much stronger linkage disequilibrium between the marker haplotypes and the disease in Swedish fragile X chromosomes than in Czech and most other previously studied Caucasian populations. Two haplotypes accounted for 64% of Swedish fragile X chromosomes and for only 14% of normal chromosomes. Neither of these two haplotypes was found in Czech chromosomes, but the most common Swedish fragile X haplotype is the same as that reported to be predominant in Finnish fragile X patients. Linkage disequilibrium was observed in the Czech fragile X chromosomes but the haplotypes were more diverse and similar to those observed in other Caucasian populations. The most prevalent Swedish fragile X haplotype was traced back from affected males to common ancestors in the early 18th century. This indicates an apparently silent segregation of fragile X alleles through up to nine generations. The geographical distribution of the two major at-risk haplotypes in Sweden suggests that they were present among early settlers in different parts of the country.

Specific binding of [11C]-N-methyl-spiperone to striatal dopamine D2 receptors was assessed using positron emission tomography (PET) in 6 patients with adult-onset focal dystonia (predominantly spasmodic torticollis) and in 5 healthy subjects. No significant difference in average specific striatal tracer uptake between patients and healthy subjects was found. However, in the 5 patients showing lateralisation of clinical signs a trend to higher striatal tracer uptake in the contralateral hemisphere was observed.

A large Swedish family with more than 250 cases of Best's macular dystrophy has been clinically and genetically studied. The gene was traced to a couple born in central Sweden in the 17th century. Highly significant evidence for genetic linkage to DNA markers on chromosome 11q13 was detected. A lod score of 15.12 was obtained at recombination fraction 0.01 with DNA marker INT2 (also called FGF3). The retinally expressed gene ROM1, which maps to the same chromosomal region is a candidate for this genetic disease.

A new, Swedish case with Tay or IBIDS syndrome is presented. The boy had growth and mental retardation, congenital ichthyosis and brittle hair. He was the only child in an uncle–niece marriage. The boy suffered recurrent infections and died at the age of 3 years from pneumonia. Clinical data on 15 cases are presented from a study of the literature.

The hereditary dystonias include a clinically heterogeneous group of movement disorders varying in symptoms, age of onset, and drug responsiveness. Dopamine beta-hydroxylase (DBH), the enzyme that converts dopamine to norepinephrine, has been implicated in dystonia because of increased serum levels of DBH in some patients, the influence of catecholaminergic drugs on the human phenotypes, and altered norepinephrine levels in several brain regions in dystonia patients and in genetically dystonic rodents. In addition, markers linked to the dystonia gene in two ethnic groups map close to the DBH locus on human chromosome 9q34. Here we evaluate the inheritance of restriction fragment length polymorphisms near the DBH gene in families with four subtypes of hereditary dystonia: Jewish and non-Jewish, early onset, generalized idiopathic torsion dystonia (ITD); dopa-responsive dystonia; and myoclonic dystonia. In all families, obligate recombination events were observed between the DBH and dystonia genes, thus excluding the DBH gene as the primary defect.

Diagnosis of the carrier status of the fragile X [fra(X)] syndrome was made in 2 unrelated women who did not express the fragile site. Both were related to several individuals with a typical fra(X) phenotype and the marker X chromosome. A restriction fragment length polymorphism (RFLP) approach was used with probes that flank the fra(X) locus (FRAXA). The loci used for risk calculations of the fra(X) genotype were DXS98 and DXS105 on the centromeric side and a recently characterized locus, DXS304, on the telomeric side. Coincidence correction for the distances between marker loci and FRAXA was made according to the Kosambi function. The DNA marker test gave the risk for one female to be a carrier of 99.7-99.9%. In another family a female was excluded from being a carrier with a probability of greater than 99.7%. The DNA marker U6.2, defining the locus DXS304, has increased the reliability of DNA based diagnosis of carrier status for females-at-risk. It is concluded that DNA analysis can serve as a valuable complement to chromosome analysis in families informative for the more closely linked flanking markers.

Most studies of fragile X [fra(X)] families are able to document mental impairment only by family history. Using Swedish historical archives and the unique parish catechetical meeting records it is possible to document qualitative phenomena such as literacy for over 100 years. In this way it was possible to identify 7 individuals with mental retardation living in the nineteenth century in an earlier published fra(X) pedigree. Four of them were female. At the present time another 4 severely mentally retarded females with the fra(X) syndrome have been diagnosed in this family. The high prevalence of mentally retarded females might indicate a variant form of the fra(X) syndrome in this family.

Amyloid fibrils were isolated from the vitreous body from a heterozygous and and a homozygous individual diagnosed as FAP I (transthyretin met-30) by RFLP. On SDS-PAGE the intact TTR monomer (17 kDa) as well as a dimer was seen. The dimer form was more prominent under nonreducing conditions. Two other bands were also found. The larger 14 kDa band was identified by protein sequencing to correspond to amino acids 49-127, possibly cleaved at a putative serine protease site between amino acids 48 and 49 (lys-thr). A smaller fragment containing a cystein group probably represents the 1-48 fragment or parts of it.

The molecular structure of the Met-30 variant of human serum prealbumin (transthyretin) has been determined by x-ray crystallography to 2.3 A resolution. Refinement using XPLOR and the Konnert-Hendrickson constrained least-squares programs has now reached the crystallographic residual R = 23%. All 127 residues of both independent protein molecules are present, including low density for residues 1-9 and 124-127, which were not found by Blake, et al. in the structure of normal human prealbumin. At the present stage of refinement the two protein molecules in the crystallographic asymmetric unit are still constrained to obey a local 2-fold rotation axis. The mutated residue (30) is securely positioned in the interior of the molecule. In the vicinity of residue 30, the beta sheets have been shifted from 0.5 to 1.0 Angstroms in comparison to the structure of normal prealbumin and the size of the thyroxine binding site has been increased by about 0.8 A.

In the farming community of the sub-district of Meskan and Mareko in central Ethiopia, where the prevalence of epilepsy is knoen to be 5.2/1000, a door-to-door survey was undertaken in 1546 sampled households to find out public attitudes to epilepsy. Nearly 64% of the respondents were in the age group of 14–50 years, and 58.6% were women. The majority *86%) were illiterate, and 94% had incomes of a subsistence level; 89% had heard or witnessed seizures. Traditional views on the association of evil spirits and superstition was prevalent. By 45% of the interviewees, the disease was believed to be contagious through physical contacts during an attack. Although there was sympathetic concern in the community for the person suffering from epilepsy, negative attitudes were strong on matrimonial associations, sharing of accommodation and physical contacts with affected persons, particularly when there were obvious signs and frequent attacks by seizures. The study demonstrates that the rural community has very poor knowledge of the causes and nature of epilepsy, and this has resulted in social deprivations and at times, rejection of the sufferers.