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)

A novel missense mutation in the mediator of RNA polymerase II transcription subunit 12 (MED12) gene has been found in the original family with Lujan syndrome and in a second family (K9359) that was initially considered to have Opitz-Kaveggia (FG) syndrome. A different missense mutation in the MED12 gene has been reported previously in the original family with FG syndrome and in five other families with compatible clinical findings. Neither sequence alteration has been found in over 1400 control X chromosomes. Lujan (Lujan-Fryns) syndrome is characterised by tall stature with asthenic habitus, macrocephaly, a tall narrow face, maxillary hypoplasia, a high narrow palate with dental crowding, a small or receding chin, long hands with hyperextensible digits, hypernasal speech, hypotonia, mild-to-moderate mental retardation, behavioural aberrations and dysgenesis of the corpus callosum. Although Lujan syndrome has not been previously considered to be in the differential diagnosis of FG syndrome, there are some overlapping clinical manifestations. Specifically, these are dysgenesis of the corpus callosum, macrocephaly/relative macrocephaly, a tall forehead, hypotonia, mental retardation and behavioural disturbances. Thus, it seems that these two X-linked mental retardation syndromes are allelic, with mutations in the MED12 gene.
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PMID:The original Lujan syndrome family has a novel missense mutation (p.N1007S) in the MED12 gene. 1736 3

Polymalformative syndromes are always a clinical challenge for their complexity and sometimes for their rarity. Authors present the case of a girl with peculiar facies, macrocephaly, axial hypotonia, and severe development delay. Cerebral magnetic resonance showed polymicrogyria. Cytogenetics revealed a 46,XX,der(1)(qter-->p36.13::q42.3-->qter) karyotype. This is the third case described to date. Isolated partial deletions or trisomy, although rare, are more frequently reported. None of these genetic findings has ever been related with polymicrogyria. Molecular cytogenetic characterization was in this case of great value.
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PMID:Bilateral perisylvian polymicrogyria and chromosome 1 anomaly. 1756 May 7

N-acetylaspartic acid accumulates in Canavan Disease, a severe leukodystrophy characterized by swelling and spongy degeneration of the white matter of the brain. This inherited metabolic disease, caused by deficiency of the enzyme aspartoacylase, is clinically characterized by severe mental retardation, hypotonia and macrocephaly, and also generalized tonic and clonic type seizures in about half of the patients. Considering that the mechanisms of brain damage in this disease remain not fully understood, in the present study we investigated whether oxidative stress is elicited by N-acetylaspartic acid. The in vitro effect of N-acetylaspartic acid (10-80 mM) was studied on oxidative stress parameters: total radical-trapping antioxidant potential (TRAP), total antioxidant reactivity (TAR), chemiluminescence, thiobarbituric acid-reactive substances (TBA-RS), reduced glutathione content, sufhydryl content and carbonyl content in the cerebral cortex of 14-day-old rats. The effect of the acute administration of N-acetylaspartic acid (0.1-0.6 mmol/g body weight) was studied on TRAP, TAR, carbonyl content, chemiluminescence and TBA-RS. TRAP, TAR, reduced glutathione content and sulfhydryl content were significantly reduced, while chemiluminescence, TBA-RS and carbonyl content were significantly enhanced by N-acetylaspartic acid in vitro. The enhancement in TBA-RS promoted by N-acetylaspartic acid was completely prevented by ascorbic acid plus Trolox, and partially prevented by glutathione and dithiothreitol. The acute administration of N-acetylaspartic acid also significantly reduced TRAP and TAR, and significantly enhanced carbonyl content, chemiluminescence and TBA-RS. Our results indicate that N-acetylaspartic acid promotes oxidative stress by stimulating lipid peroxidation, protein oxidation and by decreasing non-enzymatic antioxidant defenses in rat brain. This could be another pathophysiological mechanism involved in Canavan Disease.
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PMID:N-acetylaspartic acid promotes oxidative stress in cerebral cortex of rats. 1760 35

FG syndrome was originally described as a rare syndromic cause of X-linked mental retardation associated with congenital heart disease, anal atresia, inguinal hernia, cryptorchidism, and other anomalies. However, recent reports have highlighted the more common milder presentation which has for cardinal features developmental delay, particularly in speech, neonatal hypotonia, relative macrocephaly, dysmorphic facial features, severe constipation, and few if any congenital malformations. Thus far, five separate loci have been identified on the X chromosome but attempts at finding the responsible gene have not yet been successful. Given that one putative FG locus (FGS2) is situated at Xq28, which is the location of the Filamin A gene (FLNA), and that a Filamin A mutation was reported in a boy with facial dysmorphism and constipation, it was hypothesized that Filamin A mutations could be one cause of FG syndrome. Indeed, a previously unreported FLNA missense mutation (P1291L) was detected in our patient with FG syndrome, thus supporting this hypothesis and indicating that FG syndrome could now be added to the list of Filamin A-related disorders. Filamin A studies in other children with FG syndrome would help to confirm this association.
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PMID:Filamin A mutation is one cause of FG syndrome. 1763 75

Sotos syndrome is an overgrowth condition characterized by cardinal features including excessive growth during childhood, macrocephaly, distinctive facial gestalt and various degrees of learning difficulty, and associated with variable minor features. The exact prevalence remains unknown but hundreds of cases have been reported. The diagnosis is usually suspected after birth because of excessive height and occipitofrontal circumference (OFC), advanced bone age, neonatal complications including hypotonia and feeding difficulties, and facial gestalt. Other inconstant clinical abnormalities include scoliosis, cardiac and genitourinary anomalies, seizures and brisk deep tendon reflexes. Variable delays in cognitive and motor development are also observed. The syndrome may also be associated with an increased risk of tumors. Mutations and deletions of the NSD1 gene (located at chromosome 5q35 and coding for a histone methyltransferase implicated in transcriptional regulation) are responsible for more than 75% of cases. FISH analysis, MLPA or multiplex quantitative PCR allow the detection of total/partial NSD1 deletions, and direct sequencing allows detection of NSD1 mutations. The large majority of NSD1 abnormalities occur de novo and there are very few familial cases. Although most cases are sporadic, several reports of autosomal dominant inheritance have been described. Germline mosaicism has never been reported and the recurrence risk for normal parents is very low (<1%). The main differential diagnoses are Weaver syndrome, Beckwith-Wiedeman syndrome, Fragile X syndrome, Simpson-Golabi-Behmel syndrome and 22qter deletion syndrome. Management is multidisciplinary. During the neonatal period, therapies are mostly symptomatic, including phototherapy in case of jaundice, treatment of the feeding difficulties and gastroesophageal reflux, and detection and treatment of hypoglycemia. General pediatric follow-up is important during the first years of life to allow detection and management of clinical complications such as scoliosis and febrile seizures. An adequate psychological and educational program with speech therapy and motor stimulation plays an important role in the global development of the patients. Final body height is difficult to predict but growth tends to normalize after puberty.
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PMID:Sotos syndrome. 1782 4

Paroxysmal tonic upgaze (PTU) is a childhood oculomotor syndrome of unclear etiology characterized by episodic tonic upward eye deviation with neck flexion. Neuroimaging findings are often normal and the electroencephalography during episodes is typically normal. We describe a 2-year-old boy who presented with macrocephaly, hypotonia, developmental delay and episodes of eye fluttering, head nodding and unresponsiveness. Video-EEG captured absence seizures and he was treated with valproate, which led to improvement of his seizures. However, two weeks after treatment, he developed paroxysmal episodes of "eyes up and chin down" movements lasting for hours at a time which were captured by home video. The episodes were relieved by sleep and exacerbated by fever, stress and even tactile stimulation. Increasing the dose of valproate resulted in increased frequency of the episodes. A repeat video-EEG disclosed the non-epileptic nature of these events. Discontinuation of valproate dramatically decreased the episodes. This case illustrates that paroxysmal tonic upgaze of childhood may co-exist with early onset absence epilepsy. Furthermore, valproate treatment may be associated with the development or unmasking of PTU suggesting that the pathophysiology of PTU may involve abnormal GABA neurotransmission. [Published with videosequences].
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PMID:Paroxysmal tonic upgaze of childhood with co-existent absence epilepsy. 1788 59

We report a male term newborn presenting with a congenital macrocephaly 3.5 standard deviations above the median, with a wide and tense anterior fontanel, splayed calvarial sutures, and muscular hypotonia. Antenatal head circumferences were repeatedly below the median. A postnatal head ultrasound showed a large right intracerebral mass with right lateral ventricle compression, right temporal horn dilation, and right frontal horn enlargement with lateral displacement. Additional imaging by computed tomography scan and magnetic resonance imaging was performed. A decompression was performed and histology, immunohistochemistry, and molecular biology supported the diagnosis of a primitive neuroectodermal tumor. A MYCN gene amplification assay remained negative. The incidence of neonatal brain tumors is between 1.4 and 4.1/100,000 live births. Their most common presentation is macrocephaly, hydrocephalus, stillbirth, or diagnosis by pre- or postnatal imaging. Although hydrocephaly and intra- or extracranial hemorrhage are the most frequent causes of congenital macrocephaly, this should be initially investigated by head ultrasound. A suspected malignancy will be confirmed by histopathology, immunohistochemistry, and molecular biology.
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PMID:Neonatal macrocephaly: cerebral primitive neuroectodermal tumor or neuroblastoma as an infrequent cause--a case report and review of the literature. 1790 91

Cardio-facio-cutaneous syndrome (CFC) is a multiple congenital anomaly disorder characterized by craniofacial dysmorphia, ectodermal abnormalities, congenital heart defects, and developmental and growth delay. Neurological complications associated with CFC remain to be clearly defined. Recent discovery of causative mutations in genes of the MAPK pathway (BRAF, MEK1, and MEK2) now permit accurate molecular diagnosis of CFC. The aim of the study was to characterize neurological features of participants with molecularly-confirmed CFC. Medical records, and laboratory and imaging data were reviewed for 39 mutation-positive individuals with CFC. Participants with a clinical diagnosis of CFC but a negative result on mutation screening of the BRAF, MEK1, and MEK2 genes were excluded from the study. Mean age of participants was 9 years 4 months (range 18 mo-24 y); there were 24 females and 15 males. Mutations in B RA F were present in 32 participants, MEK1 in five, and MEK2 in two participants. Hypotonia, motor delay, speech delay, and learning disability were universally present in this cohort. Macrocephaly was present in 13 participants, ptosis in 11, strabismus in 14, and nystagmus in 11 of the 22 participants who underwent a neurological exam. Corticospinal tract findings were present in seven participants. Ventriculomegaly or hydrocephalus was present in 14 of 32 participants who underwent brain imaging. Other findings on magnetic resonance imaging included prominent Virchow-Robin spaces (n=6), abnormal myelination (n=4), and structural anomalies (n=5). Seizures were present in 15 participants. No specific genotype-phenotype correlation was observed.
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PMID:Neurological complications of cardio-facio-cutaneous syndrome. 1803 35

Megalencephaly, polymicrogyria, and hydrocephalus (MPPH) syndrome is characterized by megalencephaly, perisylvian polymicrogyria, postaxial polydactyly, and hydrocephalus. Seven cases have been reported. This report presents a new sporadic patient with megalencephaly, polymicrogyria, and hydrocephalus syndrome, a girl born to healthy, nonconsanguineous parents at 38 weeks. Macrocephaly (+4 standard deviation) was present at birth. She had syndactyly instead of the postaxial polydactyly reported in the other patients. Neurologic examination showed severe diffuse hypotonia and profound developmental delay. Magnetic resonance imaging revealed enlarged lateral and third ventricles, with cavum septi pellucidi et vergae, bilateral abnormal white matter intensity, and diffuse polymicrogyria, most prominent in both the frontal and perisylvian regions. A visual evoked potential study showed increased latencies, probably caused by white matter abnormalities. At 16 months, she has never had seizures and shows profound psychomotor retardation. Results of metabolic and genetic studies were normal.
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PMID:Megalencephaly, polymicrogyria, and hydrocephalus (MPPH) syndrome: a new case with syndactyly. 1847 36

Opitz and Kaveggia [Opitz and Kaveggia (1974); Z Kinderheilk 117:1-18] reported on a family of five affected males with distinctive facial appearance, mental retardation, macrocephaly, imperforate anus and hypotonia. Risheg et al. [Risheg et al. (2007); Nat Genet 39:451-453] identified an identical mutation (p.R961W) in MED12 in six families with Opitz-Kaveggia syndrome, including a surviving affected man from the family reported in 1974. The previously defined behavior phenotype of hyperactivity, affability, and excessive talkativeness is very frequent in young boys with this mutation, along with socially oriented, attention-seeking behaviors. We present case studies of two older males with FG syndrome and the p.R961W mutation to illustrate how their behavior changes with age. We also characterize the behavior of eight additional individuals with FG syndrome and this recurrent mutation in MED12 using the Vineland Adaptive Behavior Scales 2nd edition, the Reiss Profile of Fundamental Goals and Motivation Sensitivities, and the Achenbach Child Behavior Checklist. Males with this MED12 mutation had deficits in communication skills compared to their socialization and daily living skills. In addition, they were at increased risk for maladaptive behavior, with a propensity towards aggression, anxiety, and inattention. Based on the behavior phenotype in 10 males with this recurrent MED12 mutation, we offer specific recommendations and interventional strategies. Our findings reinforce the importance of testing for the p.R961W MED12 mutation in males who are suspected of having developmental and behavioral problems with a clinical phenotype that is consistent with FG syndrome.
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PMID:Behavior of 10 patients with FG syndrome (Opitz-Kaveggia syndrome) and the p.R961W mutation in the MED12 gene. 1897 76


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