Loss Of Purposeful Use Research Articles

Expression pattern of cdkl5 during zebrafish early development: implications for use as model for atypical Rett syndrome.

Atypical Rett syndrome is a child neurodevelopmental disorder induced by mutations in CDKL5 gene and characterized by a progressive regression in development with loss of purposeful use of the hands, slowed brain and head growth, problems with walking, seizures, and intellectual disability. At the moment, there is no cure for this pathology and little information is available concerning animal models capable of mimicking its phenotypes, thus the development of additional animal models should be of interest to gain more knowledge about the disease. Zebrafish has been used successfully as model organism for many human genetic diseases; however, no information is available concerning the spatial and temporal expression of cdkl5 orthologous in this organism. In the present study, we identified the developmental expression patterns of cdkl5 in zebrafish by quantitative PCR and whole-mount in situ hybridization. cdkl5 is expressed maternally at low levels during the first 24h of development. After that the expression of the gene increases significantly and it starts to be expressed mainly in the nervous system and in several brain structures, such as telencephalon, mesencephalon and diencephalon. The expression patterns of cdkl5 in zebrafish is in accordance with the tissues known to be affected in humans and associated to symptoms and deficits observed in Rett syndrome patients thus providing the first evidence that zebrafish could be an alternative model to study the molecular pathways of this disease as well as to test possible therapeutic approaches capable of rescuing the phenotype.

LE SYNDROME DE RETT

Rett syndrome is a degenerative neurological disorder with onset between 6 and 18 months of age. We report one case of Rett syndrome affecting a 2 years 6 months old girl. She had presented an earty deterioration of higher brain function with dementia and autistic behavior, loss of purposeful use of the hands and deceleration of head growth. No specific laboratory test for Rett syndrome has been set up yet and there are many unanswered questions about this disease.

RETT's syndrome in Korea: report of two cases

Rett's syndrome(RS) is a progressive neurodegenerative disorder characterized by exclusive occurrence in females, autistic behavior, dementia, gait ataxia, loss of purposeful use of the hands with stereotypic hand movement, and seizures. Initially RS was considered to be very rare; however, recent reports suggest that the prevalence is considerably higher and occurrence is world-wide. Because the pathophysiological process remains unknown, the diagnosis of RS is based mainly on its characteristic clinical features and course. We experienced two cases of RS which, to our knowledge, are the first reported in Korea. It is quite possible that many patients with RS not yet being diagnosed in Korea.

Rett's syndrome. Correlation of electroencephalographic characteristics with clinical staging.

Rett's syndrome is a progressive disorder in female patients, characterized by autistic behavior, dementia, ataxia, loss of purposeful use of the hands, and seizures. The electroencephalographic (EEG) characteristics of 17 patients with Rett's syndrome, studied between the ages of 1 and 16 years, are reported and correlated with a recently proposed system of clinical staging. Although a specific diagnostic EEG pattern was not seen in these patients, we did observe a progressive deterioration in the EEG, characterized by a slowing of EEG activity, a loss of normal sleep EEG characteristics, and the appearance of multifocal epileptiform abnormalities, followed by a pattern of generalized slow spike-wave activity. These characteristics appear to be typically seen in patients with Rett's syndrome and can be correlated with clinical staging. The EEG may be of benefit in identifying variations or subgroups in patients with Rett's syndrome as a complement to the clinical examination.

Rett's syndrome: characterization of respiratory patterns and sleep.

Rett's syndrome is a progressive disorder that occurs in females and is characterized by autistic behavior, dementia, ataxia, loss of purposeful use of the hands, and seizures. Patients with Rett's syndrome have been observed to have stereotyped hand movements (hand-washing) and to exhibit intermittent hyperventilation. To characterize more precisely the sleep and respiratory patterns associated with this disorder, polygraphic studies were made during sleep and wakefulness in 11 patients with this syndrome. These studies showed abnormal respiratory patterns during wakefulness, and abnormal sleep and electroencephalographic characteristics. The patients had decreased percentages of rapid-eye-movement sleep, and during wakefulness, a pattern of disorganized breathing was observed in all 11 patients and consisted of hypoxia followed by a period of increased respiratory rate and effort. The occurrence of disorganized breathing and compensatory hyperpnea during wakefulness with regular, continuous breathing during sleep is characteristic of Rett's syndrome and suggests an altered or impaired voluntary/behavioral respiratory control system.

Rett syndrome. A commonly overlooked progressive encephalopathy in girls.

We report 15 cases of Rett syndrome, a slowly progressive disorder that occurs only in girls and is characterized by early deterioration of higher brain function with dementia and autistic behavior, loss of purposeful use of the hands, and deceleration of head growth. Epilepsy, with minor motor seizures being the predominant type, has its onset between 2 and 4 years of age in the majority of cases. Additional features include an extrapyramidal disorder with dystonia and choreoathetosis, and lactic acidemia. A precise biochemical marker of this disorder has not been identified.

Reduction of Biogenic Amine Levels in the Rett Syndrome

The Rett syndrome is a progressive disorder in female patients that is characterized by autistic behavior, dementia, ataxia, loss of purposeful use of the hands, and seizures. The results of laboratory investigations are usually normal, with the exception of electroencephalography. In an attempt to understand the pathogenesis of this syndrome, we assayed biogenic amine metabolites in the cerebrospinal fluid of six patients, 2 to 15 years of age. 3-Methoxy-4-hydroxyphenylethylene glycol (MHPG, a metabolite of norepinephrine), homovanillic acid (a metabolite of dopamine), and 5-hydroxyindoleacetic acid (5-HIAA, a metabolite of serotonin) were quantitated by a method involving gas chromatography and mass spectrometry. Levels of MHPG and homovanillic acid were significantly reduced in all the patients as compared with those in controls of similar age (P = 0.01 and 0.008, respectively). The reduction in the level of 5-HIAA was not significantly different from that in the controls (P = 0.15). These findings suggest an underlying disorder of biogenic amines in the Rett syndrome and may provide new insight into its pathogenesis.

1670 BIOGENIC AMINE METABOLISM IN RETT'S SYNDROME

Rett's Syndrome is a progressive disorder in females characterized by autistic behavior, dementia, ataxia, loss of purposeful use of the hands and seizures. Extensive laboratory investigations are usually normal with the exception of electroencephalography. To date no biochemical abnormalities have been reported. In an attempt to find a lead to the pathogenesis of this syndrome we assayed biogenic amine metabolites in the cerebrospinal fluid (CSF) of six patients, age 2-15 years, with Rett's Syndrome. The following metabolites were assayed and compared to age matched controls: 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA). Results are as follows: Mean ± S.D. (ng/ml). Thus, norepinephrine, dopamine, and serotonin metabolites are significantly reduced in the CSF of patients with Rett's Syndrome. This may provide new insight into the pathogenesis and future therapeutic intervention in these patients.

A progressive syndrome of autism, dementia, ataxia, and loss of purposeful hand use in girls: Rett's syndrome: report of 35 cases.

Thirty-five patients, exclusively girls, from three countries had a uniform and striking progressive encephalopathy. After normal general and psychomotor development up to the age of 7 to 18 months, developmental stagnation occurred, followed by rapid deterioration of higher brain functions. Within one-and-a-half years this deterioration led to severe dementia, autism, loss of purposeful use of the hands, jerky truncal ataxia, and acquired microcephaly. The destructive stage was followed by apparent stability lasting through decades. Additional insidious neurological abnormalities supervened, mainly spastic parapareses, vasomotor disturbances of the lower limbs, and epilepsy. Prior extensive laboratory investigations have not revealed the cause. The condition is similar to a virtually overlooked syndrome described by Rett in the German literature. The exclusive involvement of females, correlated with findings in family data analyses, suggests a dominant mutation on one X chromosome that results in affected girls and nonviable male hemizygous conceptuses.