Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carbohydrate-deficient glycoprotein syndrome type 1 (CDGS-1) is an autosomal recessive hereditary metabolic disorder, the gene locus of which is chromosome 16p13. The disorder is characterised by genetic heterogeneity, and by decrease in the gene product, phosphomannomutase 2, though the heterogeneity is far less manifest in affected Swedish families. Its incidence is 1/80,000 live births, and the under-5 mortality rate over 30 per cent. The causes of death are liver failure, cardiac tamponade, haemorrhaging, and severe infection. The characteristic biochemical aberration is the occurrence of deficient carbohydrate chains in many but not all circulating glycoproteins, and the serum and blood concentrations of some glycoproteins may be above or below normal. These changes may improve over time, but never normalise. The clinical picture is generally more problematic during the first years of life when psychomotor retardation is complicated by failure to thrive, liver dysfunction, pericardial effusions, and stroke-like episodes. In addition, strabismus, lipocutaneous anomalies, and gluteal fat pads are always present, and muscular hypotonia and restricted joint mobility are common. Failure to thrive is common, with vomiting and diarrhoea and subsequent slow growth. Inflammation is a constant finding in the liver, and very common in the small bowel. Pancreatic function is also affected. Pericardial effusion has been reported in 50 per cent of the youngest children, requiring pericardectomy in 30 per cent of cases. Haemorrhaging and thromboembolic complications may occur, and the serum concentrations of several factors and inhibitors are low, particularly those of factors V and XI, protein C and antithrombin. Stroke-like episodes occur in about 30 per cent of cases, often following an infection, with coma lasting for hours to several days. Such sequelae as hemiplegia, blindness, and other focal neurological pathology have been observed transiently. Diagnosis is based on the serum carbohydrate-deficient transferrin level, verified by isoelectric focusing. Molecular genetic procedures enable point mutations to be identified and prenatal diagnosis to be performed in many families.
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PMID:[CDGS-1--a recently discovered hereditary metabolic disease. Multiple organ manifestations, incidence 1/80,000, difficult to treat]. 988 93

A small ring-shaped supernumerary marker chromosome (SMC) was detected in 50% of metaphase cells in an 18-month-old boy with mental retardation and multiple congenital anomalies. Conventional cytogenetic methods had failed to identify the origin of the marker. When the patient was age 11.5 years, we defined the origin of the SMC by fluorescence in situ hybridization using a battery of centromere-specific DNA probes. The marker was positive with the probe for locus D2Z. More detailed characterization was achieved by using chromosome 2 arm-specific and marker-specific DNA libraries, which were constructed by microdissection of the two arms chromosome 2 and SMC with subsequent amplification of the chromosomal material by a degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR). The marker was identified as r(2)(p11.2-->q14.1). The propositus had dolichocephaly, coarse hair, low-set ears, exophthalmos, epicanthal folds, strabismus, depressed nasal bridge, high-arched palate, excess of skin on the neck, tapered fingers with mild clinodactyly, talipes varus on the right, inguinal hernia, hypogenitalism, muscular hypotonia, and mental retardation. This is the first case of SMC derived from chromosome 2 that was characterized by forward and reverse chromosome painting.
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PMID:Characterization of a small supernumerary ring marker derived from chromosome 2 by forward and reverse chromosome painting. 1056 73

Carbohydrate-deficient glycoprotein syndrome (CDGS) is a newly delineated group of inherited multisystemic disorders associated with abnormal glycosylation of a number of serum glycoproteins. Several types have been described on the basis of clinical presentation and biochemical changes of the glycosylation of serum transferrin and attributed to different enzymatic defects; their clinical presentations are fully different and a clinical heterogeneity is observed within a same type of CDGS. Patients with CDGS type la usually present with neurologic (hypotonia, strabismus and cerebellar hypoplasia) and cutaneous (inverted nipples, abnormal distribution of adipose tissue) abnormalities, together with multivisceral involvement (digestive, hepatic, cardiac, renal). However, neurologic and cutaneous symptoms may be absent, so that CDGS must be looked for in case of unexplained organ failure such as isolated liver insufficiency, cardiomyopathy, pericarditis, tubulopathy, nephrotic syndrome, vascular accident or retinitis pigmentosa. Patients with CDGS type Ib present with liver disease, enteropathy and hypoglycemia without neurologic involvement. These patients are successfully treated with oral mannose administration emphasizing the importance of making the diagnosis. Patients with CDGS type Ic present with mild psychomotor retardation and seizures. Patients with CDGS type II have psychomotor retardation association with severe gastrointestinal disorder, dysmorphic features and abnormal electroretinogram. Other types (III, IV) are less clearly defined and the clinical presentation includes convulsive encephalopathy. Biological abnormalities such as mild hepatic cytolysis, hematologic and hormonal abnormalities are consistently observed in CDGS type I, as well as renal hyperechogeneity, leading one to look for this syndrome when they are associated. Until now, only four enzymatic deficiencies have been identified (types Ia, Ib, Ic, II).
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PMID:[Carbohydrate-deficient blood glycoprotein syndrome]. 1070 Oct 64

Congenital disorders of glycosylation (CDGs) are a rapidly enlarging group of inherited diseases with abnormal N-glycosylation of glycoconjugates. Most patients have CDG-Ia, which is due to a phosphomannomutase (PMM) deficiency. In this article, we report that a significant portion (9 of 54) of patients with CDG-Ia had a rather high residual PMM activity in fibroblasts included in the normal range (means of the controls +/- 2 SD) and amounting to 35%-70% of the mean control value. The clinical diagnosis of CDG-Ia was made difficult by the fact that most (6 of 9) of these patients belong to a subgroup characterized by a phenotype that is milder than classical CDG-Ia. These patients lack some of the symptoms that are suggestive for the diagnosis, such as inverted nipples and abnormal fat deposition, and, as a mean, had higher residual PMM activities in fibroblasts (2.05+/-0.61 mU/mg protein, n=9; vs. controls 5.34+/-1.74 mU/mg protein, n=22), compared with patients with moderate (1.32+/-0.86 mU/mg protein, n=18) or severe (0.63+/-0.56 mU/mg protein, n=27, P<.001) cases. Yet they all showed mild mental retardation, hypotonia, cerebellar hypoplasia, and strabismus. All of them had an abnormal serum transferrin pattern and a significantly reduced PMM activity in leukocytes. Six of the nine patients with mild presentations were compound heterozygotes for the C241S mutation, which is known to reduce PMM activity by only approximately 2-fold. Our results indicate that intermediate PMM values in fibroblasts may mask the diagnosis of CDG-Ia, which is better accomplished by measurement of PMM activity in leukocytes and mutation search in the PMM2 gene. They also indicate that there is some degree of correlation between the residual activity in fibroblasts and the clinical phenotype.
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PMID:High residual activity of PMM2 in patients' fibroblasts: possible pitfall in the diagnosis of CDG-Ia (phosphomannomutase deficiency). 1115 36

In this report, we present a 14-year-old girl, born to consanguineous parents, who presented with severe mental retardation, hypotonia, short stature, and congenital joint contractures. The craniofacial features were scaphocephaly, thin/long and immobile face, marked hypoplasia of the midface, temporal narrowness, blepharophimosis, palpebral ptosis, and strabismus. The combination of such a distinctive craniofacial appearance and psychomotor retardation allows us to recognize a new case of the Marden-Walker syndrome. Our patient represents one of the rare cases in which consanguineous mating supports the autosomal-recessive pattern of inheritance of this condition. Furthermore, through refining the phenotype of a surviving patient, this report may contribute to a better recognition of this disorder in older affected children.
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PMID:Additional case of Marden-Walker syndrome: support for the autosomal-recessive inheritance adn refinement of phenotype in a surviving patient. 1129 26

A 10-year-old mentally retarded boy with terminal 6q25 deletion, dysmorphism and striking abnormal behaviour is reported. The main abnormal physical features recorded at different ages consisted of hydrocephalus, axial hypotonia, absence of spontaneous prehension, long face, synophris, hypertelorism with epicanthic folds, internal alternating strabismus, retinal abnormalities with macular degeneration, beaked nose, long philtrum, high-arched palate, lumbar spina bifida, right paravertebral dimple at the upper sacral region, prominent coccyx, broad thumbs and great toes, fetal pads and cryptorchidism. The special behavioural difficulties were made of restlessness, hyperactivity, obsessive compulsive reactions with a self-injurious tendency and episodes of apparently voluntary vomiting crisis concomitant with stress periods. A review of the available literature strongly suggests that individuals with small chromosomal deletions are at high risk of developing behavioural problems.
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PMID:Terminal 6q25.3 deletion and abnormal behaviour. 1169 83

A boy with an unspecific symptomatology consisting of mental retardation, strabismus, hypotonia and mild ataxia was diagnosed with a congenital disorder of glycosylation (CDG). Neither cerebellar atrophy nor dysmorphic features were present. The serum transferrin band pattern obtained by isoelectric focusing(IEF) showed a strongly elevated disialotransferrin band together with only slightly elevated asialotransferrin, thus a type I pattern. This is a new CDG classified CDG-x since CDG-la, -b, -c, -d and -e were excluded. Quantitative differences to the type 1 pattern of a CDG-la patient with a moderate to severe course were confirmed by densitometric evaluation of the gels and by SDS gel electrophoresis. Liver biopsy showed lysosomal inclusions suggesting a pre-Golgi defect. This patient's case supports the approach to include isoelectric focusing of serum transferrin in the diagnostic work-up of patients with unexplained symptoms.
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PMID:A new subtype of a congenital disorder of glycosylation (CDG) with mild clinical manifestations. 1187 May 87

Congenital disorders of glycosylation (CDG) are a group of metabolic disorders with multisystemic involvement characterized by abnormalities in the synthesis of N-linked oligosaccharides. The most common form, CDG-Ia, resulting from mutations in the gene encoding the enzyme phosphomannomutase (PMM2), manifests with severe abnormalities in psychomotor development, dysmorphic features and visceral involvement. While this disorder is panethnic, we present the first cases of CDG-Ia identified in an African American family with two affected sisters. The proband had failure to thrive in infancy, hypotonia, ataxia, cerebellar hypoplasia and developmental delay. On examination, she also exhibited strabismus, inverted nipples and an atypical perineal fat distribution, all features characteristic of CDG-Ia. Direct sequencing demonstrated that the patient had a unique genotype, T237M/c.565-571 delAGAGAT insGTGGATTTCC. The novel deletion-insertion mutation, which was confirmed by subcloning and sequencing of each allele, introduces a stop codon 11 amino acids downstream from the site of the deletion. The presence of this deletion-insertion mutation at cDNA position 565 suggests that this site in the PMM2 gene may be a hotspot for chromosomal breakage.
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PMID:A deletion-insertion mutation in the phosphomannomutase 2 gene in an African American patient with congenital disorders of glycosylation-Ia. 1189 94

To assess the clinical impact of microcephaly among children with developmental disabilities, we reviewed the charts of 1393 consecutive patients from birth to 5 years of age referred to our child development center. Comparisons were made between normal and low IQ microcephalic patients and between children with cerebral palsy with and without small head circumference. Microcephaly was detected in 15.4% of patients. Although mental retardation was more common among microcephalic children (P < .001), almost half had normal intelligence. Prematurity (P < .001), perinatal asphyxia (P < .001), small for gestational age (P < .001), respiratory distress syndrome (P < .001), and brain hemorrhage (P < .001) were associated with microcephaly. Hypotonia (P < .001) and spasticity (P < .001) were the most common neurologic findings. Cerebral palsy (P < .001), growth retardation (P < .001), epilepsy (P < .001), and strabismus (P < .001) were the main associated diagnoses found. Mental retardation was significantly more common among microcephalic patients with cerebral palsy than among normocephalic ones (P < .0004). Microcephaly is common among children evaluated for developmental disabilities. Many of these patients have normal or borderline IQ. Of several perinatal conditions associated with later microcephaly, respiratory distress syndrome and intraventricular hemorrhage show the strongest correlation. Mental retardation is not a risk factor for other neurologic complications in microcephalic children. However, in children with cerebral palsy, microcephaly is a risk factor for mental retardation.
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PMID:Significance of microcephaly among children with developmental disabilities. 1195 71

The medical findings from a population-based study of Prader-Willi syndrome (PWS) are discussed (in which birth incidence of PWS was estimated at 1:22,000 and death rate at over 3% per annum). In this study the prevalence of specific medical disorders that might account for a shortened life expectancy were investigated. Of all people with a possible diagnosis of PWS, only those meeting clinical criteria and/or with a confirmed genetic diagnosis were included in the study. Sixty-six individuals, 40 males and 26 females with a mean age of 19 years (range of 0 to 46 years) agreed to participate in the population-based study group. A prevalence rate of 25% for non-insulin dependent diabetes mellitus (NIDDM) was found in adults. Mean age at onset was 20 years. Those with NIDDM had a higher past maximum body weight and a greater likelihood of positive family history. Nearly 50% across the age groups reported a history of recurrent respiratory infections. High rates of fractures (29%), leg ulceration (22% in adults), sleep disorders (20%), and severe scoliosis (15% in childhood) were also reported. It is postulated that hypotonia is a possible contributory factor to the risk of strabismus, scoliosis, and respiratory infections. Other causes of morbidity, in particular the high rates of NIDDM, may be due to a failure to manage over-eating resulting in severe obesity. Early diagnosis and clear guidance to families about these risks and how they might be prevented is recommended. It is hypothesized that the high pain threshold may result in the presence of some illness not being apparent.
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PMID:Prevalence of, and risk factors for, physical ill-health in people with Prader-Willi syndrome: a population-based study. 1199 93


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