1/46. Genetic factors in human sleep disorders with special reference to Norrie disease, prader-willi syndrome and Moebius syndrome.Sleep-wake problems are common in specific inborn errors of metabolism and structure of the central nervous system. Psychological factors, behavioural difficulties, metabolic disturbances, and widespread rather than focal damage to the nervous system are present in many of these diseases and all influence the sleep-wake cycle. However, a number of conditions cause relatively focal damage to the neuroanatomical substrate of sleeping and waking. These include fatal familial insomnia, with involvement of the prion protein gene on chromosome 20, Norrie disease, the prader-willi syndrome and the Moebius syndrome. The last three important conditions, although rare, are considered in detail in this review. They result in sensory deprivation, hypothalamic and mid-brain damage, and involve the X-chromosome, chromosome 15, and chromosome 13, respectively. These conditions cause a wide variety of sleep disturbance, including parasomnias, daytime sleepiness, and a condition like cataplexy. The place of the relevant gene products in normal sleep regulation needs further exploration.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
2/46. Maternal uniparental disomy for chromosome 14 in a boy with a normal karyotype.We report on a boy with a maternal uniparental disomy for chromosome 14 (UPD(14)). At 7 years of age he was referred to us by the paediatrician because of symptoms of prader-willi syndrome (PWS). He showed short stature, obesity, mild developmental delay, cryptorchidism, and some mild dysmorphic features. The history further indicated intrauterine growth retardation at the end of the pregnancy. His mother was 44 years of age at the time of his birth. After birth he showed hypotonia with poor sucking, for which gavage feeding was needed. Motor development was delayed. After 1 year he became obese despite a normal appetite. Recurrent middle ear infections, a high pain threshold, and a great skill with jigsaw puzzles were reported. There were no behavioural problems or sleep disturbance. Chromosomal analysis was normal (46,XY). dna analysis for prader-willi syndrome showed no abnormalities. Two years later he was re-examined because we thought his features fitted the PWS-like phenotype associated with maternal UPD(14). At that time precocious puberty was evident. dna analysis showed maternal heterodisomy for chromosome 14. In all the previously described 11 cases with maternal UPD(14), a Robertsonian translocation involving chromosome 14 was detected cytogenetically before dna analysis. This is the first report of diagnosis of maternal UPD(14) based on clinical features. This finding underlines the importance of dna analysis for maternal UPD(14) in patients with a similar PWS-like phenotype even without previous identification of a Robertsonian translocation involving chromosome 14.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
3/46. Investigation of a cryptic interstitial duplication involving the Prader-Willi/angelman syndrome critical region.A 3-year-old female referred with developmental delay, hypotonia and seizures was found to have a cryptic interstitial duplication of the Prader-Willi/Angelman critical region (PWACR). Her clinical features form part of a common phenotype characteristic of PWACR duplications including developmental delay, behavioural problems and speech difficulties. Microsatellite analysis showed that the duplication had arisen de novo, was maternal in origin and involved the entire 4-Mb PWACR between the common deletion breakpoints. The existence of cryptic rearrangements emphasises the need for molecular tests alongside conventional cytogenetics when investigating abnormalities involving this imprinted region.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
4/46. Multisystem involvement in congenital insensitivity to pain with anhidrosis (CIPA), a nerve growth factor receptor(Trk A)-related disorder.Congenital insensitivity to pain with anhidrosis (CIPA), a rare autosomal recessive disorder, is characterized by insensitivity to pain, self-mutilating behaviour, anhidrosis and recurrent hyperpyrexia. It is a hereditary sensory and autonomic neuropathy, also classified as HSAN, due to a defect of the receptor for nerve growth factor. CIPA is the first human genetic disorder caused by a defect in the neurotrophin signal transduction system. This is the first clinical report of CIPA patients characterized on molecular grounds. The clinical phenotypes of our patients show that CIPA is characterized by a multisystem involvement besides the nervous system, including bone fracture with slow healing, immunologic abnormalities, such as low response to specific stimuli, chronic inflammatory state ending in systemic amyloidosis. The molecular characterization allows a better understanding of most of the clinical features.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
5/46. Fatal familial insomnia: clinical, neuropathological, and genetic description of a Spanish family.The clinical presentation and evolution, neuropathological findings, and genotyping of three members of a Spanish family affected with fatal familial insomnia are reported. The mother and two of her offspring developed a rapidly evolving disease with insomnia and behavioural disorders as the initial symptoms and died between 5 and 10 months after the onset of the illness. Frontal brain biopsy in the mother disclosed only non-significant spongiosis, and full neuropathological examination of her offspring showed thalamic and olivary degeneration with isolated focal cortical spongiosis. Genetic examination could only be performed in the contemporary patients and both harboured the prion protein (PrP) 178Asn mutation and homozygous 129 Met/Met genotype.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
6/46. Interchromosomal effects for chromosome 21 in carriers of structural chromosome reorganizations determined by fluorescence in situ hybridization on sperm nuclei.We have used dual color fluorescence in situ hybridization (FISH) on decondensed sperm heads from four carriers of structural chromosome reorganizations, viz. t(3;15), t(Y;7), t(13;22) and inv(9), to assess the possible existence of an interchromosomal effect (ICE) on the segregation of chromosome 21. In the carriers of t(Y;7), t(13;22) and inv(9), all results were within the limits described in controls. A highly significant increase (P<0.0001) of disomy 21 (1.90% v 0.37%), which could be considered as a positive ICE, was observed in the t(3;15) carrier. Significantly higher percentages (P<0.0001) of diploid sperm (5.71% v. 0.27%) were also observed in this patient. Our results suggests that the occurrence of an ICE may depend on the reorganization and on the chromosome and chromosome regions involved, resulting in a particular meiotic behaviour (presence of unsynapsed regions, preferential meiotic configurations) that could lead to the observed increase in chromosome 21 disomies. Further studies with this technical approach in a wide range of structural reorganizations could help to elucidate the actual occurrence of ICEs.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
7/46. Otorhinolaringologic manifestation of smith-magenis syndrome.smith-magenis syndrome (SMS) is a multiple congenital anomaly/mental retardation (MCA/MR) syndrome link to a contiguous-gene deletion syndrome, involving chromosome 1 7p 11.2,whose incidence is estimated to be 1:25,000 livebirth. SMS is characterised by a specific physical, behavioural and developmental pattern. The main clinical features consist of a broad flat midface with brachycefaly, broad nasal bridge, brachydactily, speech delay, hoarse deep voice and peripheral neuropathy. Behavioural abnormalities include hypermotility, self-mutilation and sleep disturbance. This report defines the otorhinolaryngological aspects of a new case of SMS, confirmed by cytogenetic-molecular analysis, in a 9 year old girl affected by chronic otitis media, deafness and sinusitis, who presented with typical clinical signs and symptoms.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
8/46. Familial paroxysmal exercise-induced dyskinesia, epilepsy, and mental retardation in a family with autosomal dominant inheritance.Only few sporadic and familial cases of paroxysmal exercise-induced dyskinesia (PED) have been described in literature. PED associated with familial epilepsy has been rarely reported. We describe a family in which six members in different generations were affected by a long-lasting PED, with childhood onset in five cases. fasting and stress were also precipitating factors. All the subjects, moreover, showed epileptic seizures during childhood and adolescence. In addition, in all cases a condition of mild mental retardation was also documented, associated in some cases, with irritable and impulsive behaviour. Clinical, neurophysiological, neuroimaging and neuropsychological findings were reported. The homogeneous recurrence of this particular clinical picture in members of three generations emphasised a common genetic basis. In our patients, PED is transmitted as an autosomal dominant trait, with age-dependent penetrance, without evidence of genetic anticipation. The neurophysiological findings suggest a condition of hyperexcitability in the muscular and brain membrane, due to a ion channels disorder.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
9/46. A profoundly mentally handicapped woman with a ring chromosome 22.A small thirty-eight-year-old profoundly retarded woman is decribed who has a ring chromosome identified by banding techniques. Details are given of her behaviour, anthropometry, dermatoglyphics, karyotype and biochemistry with extensive investigations of her blood proteins and enzymes. Other described cases of ring 21 and 22 are reviewed. There is so much variability among the ring 22 chromosomes that it is not considered justifiable to speak of a ring 22 syndrome.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
10/46. chorea-acanthocytosis: clinical and genetic findings in three families from the Arabian peninsula.chorea-acanthocytosis is a rare autosomal recessive disorder. Its characteristics are orofacial dyskinesia, hyporeflexia, seizures, aberrant behavior, atrophy of the caudate and putamen, and acanthocytes in the blood with a normal level of lipoproteins. We describe three families with chorea-acanthocytosis. The inheritance pattern was recessive and the average age at onset was 27 years (range, 18-35 years). The presenting symptoms were seizures, aberrant behaviour, chorea, tics, and/or abnormal gait. Phase-contrast and electron microscopy examinations of blood showed 10 to 40% acanthocytes. The lipid profile was normal except that, in one family, no prebetalipoprotein bands corresponding to the fraction of very low-density lipoprotein were seen in high-resolution lipoprotein electrophoresis. magnetic resonance imaging of the brain showed marked atrophy in the caudate and putamen; 18-fluorodeoxyglucose positron emission tomography scan showed hypometabolism in the striatum. In all three families, the disease was linked to a 6-cM region of chromosome 9q21 flanked by the recombinant markers GATA 89a11 and D9S1843. This finding strongly suggests the involvement of a single locus for this syndrome. Three different homozygous mutations of this gene have been identified. Although the clinical presentation was variable, the genetic studies on these three Saudi Arabian families with chorea-acanthocytosis provide strong evidence for a genetic locus for chorea-acanthocytosis at chromosome 9q21.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
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