Harlequin syndrome: two new cases and a management proposal.

The Harlequin syndrome is a rare autonomic disorder, characterized by unilateral diminished sweating and flushing of the face in response to heat or exercise. We present two new cases and evaluate the data of 83 patients described in the literature. We provide diagnostic and therapeutic guidelines.

Clinical spectrum of ataxia-telangiectasia in adulthood.

OBJECTIVE: To describe the phenotype of adult patients with variant and classic ataxia-telangiectasia (A-T), to raise the degree of clinical suspicion for the diagnosis variant A-T, and to assess a genotype-phenotype relationship for mutations in the ATM gene. METHODS: Retrospective analysis of the clinical characteristics and course of disease in 13 adult patients with variant A-T of 9 families and 6 unrelated adults with classic A-T and mutation analysis of the ATM gene and measurements of ATM protein expression and kinase activity. RESULTS: Patients with variant A-T were only correctly diagnosed in adulthood. They often presented with extrapyramidal symptoms in childhood, whereas cerebellar ataxia appeared later. Four patients with variant A-T developed a malignancy. Patients with classic and variant A-T had elevated serum alpha-fetoprotein levels and chromosome 7/14 rearrangements. The mildest variant A-T phenotype was associated with missense mutations in the ATM gene that resulted in expression of some residual ATM protein with kinase activity. Two splicing mutations, c.331 + 5G>A and c.496 + 5G>A, caused a more severe variant A-T phenotype. The splicing mutation c.331 + 5G>A resulted in less ATM protein and kinase activity than the missense mutations. CONCLUSIONS: Ataxia-telangiectasia (A-T) should be considered in patients with unexplained extrapyramidal symptoms. Early diagnosis is important given the increased risk of malignancies and the higher risk for side effects of subsequent cancer treatment. Measurement of serum alpha-fetoprotein and chromosomal instability precipitates the correct diagnosis. There is a clear genotype-phenotype relation for A-T, since the severity of the phenotype depends on the amount of residual kinase activity as determined by the genotype.

Neuromuscular abnormalities in ataxia telangiectasia: a clinical, electrophysiological and muscle ultrasound study.

Thirteen classical ataxia telangiectasia (A-T) patients, varying in age from 1 to 25 years, were studied clinically, electrophysiologically as well as by muscle ultrasound to chart the development and spectrum of neuromuscular abnormalities in A-T. The most prominent finding was a progressive axonal sensorimotor polyneuropathy, apparent by electromyography and muscle ultrasound from the age of 8 years and becoming clinically discernible around 12 years of age. Before the age of 8 years decreased tendon reflexes and slightly slowed sensory nerve conduction velocities could already be observed. With routine electrophysiological techniques the severe polyneuropathy precludes conclusions about the presence of anterior horn cell loss in older patients.

Distal spinal muscular atrophy as a major feature in adult-onset ataxia telangiectasia.

The authors report four adult-onset ataxia telangiectasia (AT) patients belonging to two families lacking pronounced cerebellar ataxia but displaying distal spinal muscular atrophy. AT was proven by genetic studies showing ATM mutations and a reduced level of ATM. ATM activity, as measured by phosphorylation of p53, was close to normal, indicating that the p53 response is not the only factor in preventing neural damage in anterior horn cells in AT.

Nijmegen breakage syndrome: a neuropathological study.

Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder, due to defects in the NBS1 gene and belongs to the DNA repair disorders. We report neuropathological findings of the first ever recognised case of the about 60 described cases of NBS. This patient showed severe microcephaly with a simplified gyral pattern especially in the frontal lobes. There were no signs of a degenerative disease, or of a primary migration disorder. A bulge on top of the corpus callosum, most probably a very large remnant of the involuting striae longitudinales mediales et laterales, was found. This can be considered as an incomplete development of limbic structures. The severe diminishment of neocortical neurones suggests an important role for the NBS1 gene in corticogenesis in man, as suggested earlier in animal studies of other DNA-repair genes.

[From gene to disease; ataxia telangiectasia]. / Van gen naar ziekte; ataxia-teleangiectasia.

Ataxia telangiectasia (AT) is an autosomal recessive disorder characterised by cerebellar ataxia, telangiectasia, immune defects, and a predisposition to malignancy. Chromosomal breakage is a feature. AT cells are abnormally sensitive to cell kill by ionising radiation and abnormally resistant to inhibition of DNA synthesis by ionising radiation. The responsible gene, 'ataxia telangiectasia mutated' (ATM) plays a crucial role in a signal transduction pathway, regulating the cell cycle, and in preventing damaged DNA from being reproduced. This rare genetic disorder manifests itself during childhood. The illness is progressive and most individuals die in their second or third decade of life due to infections or cancer. AT is difficult to diagnose due to its rarity and clinical heterogeneity. Both a physical examination and several laboratory tests are necessary for establishing its proper diagnosis.

Decreased immunoglobulin class switching in Nijmegen Breakage syndrome due to the DNA repair defect.

Nijmegen breakage syndrome (NBS) is a rare chromosomal-instability syndrome associated with defective DNA repair. Approximately 90% of NBS patients are homozygous for a truncating mutation of the NBS1 gene. As development of the immune system relies on recombination, which involves repair of DNA breaks, one might predict that mutations in the NBS1 gene could cause immunodeficiency. We immunologically investigated the world's largest series of NBS patients (n = 74), confirmed immunodeficiency, and found a discrepancy between relatively normal IgM concentrations, and decreased IgG and IgA concentrations. In addition, a significant relation between low IgA and low IgG levels was found. These data are compatible with a defective class switching in NBS and can be explained by a role of the NBS1 protein in DNA repair, signal transduction, cell cycle regulation or apoptosis.

Ileus in mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes.

PATIENT: A 39-year-old woman with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) who developed paralytic ileus and died of irreversible shock. METHODS: Abdominal X-ray, autopsy using light microscopy, electron microscopy and mitochondrial DNA analysis. RESULTS: Paralytic ileus was diagnosed. Several hours after admission the patient died from irreversible shock. At autopsy, ultrastructural examination of the small intestine revealed abnormal accumulation of mitochondria in smooth muscle cells. DNA analysis of the intestinal tissue showed a tRNALeu(UUR) A-->G transition at nucleotide position 3243 of the mitochondrial DNA. The amount of mutated mitochondrial DNA was markedly higher in the lamina muscularis than in the mucosa: 30% vs; 8%. CONCLUSIONS: Paralytic ileus may be due to mutated mitochondrial DNA which ultimately leads to smooth muscle dysfunction in the small intestine. Recognizing mitochondrial DNA abnormalities as a new etiopathogenetic factor of paralytic ileus may become more important in clinical medicine in the near future.

A double missense mutation in the ATM gene of a Dutch family with ataxia telangiectasia.

Ataxia telangiectasia (AT) is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectasia, immunodeficiency, elevated alpha-fetoprotein levels, chromosomal instability, predisposition to cancer, and radiation sensitivity. We report the identification of a new, double missense mutation in the ataxia telangiectasia gene (ATM) of a Dutch family. This homozygous mutation consists of two consecutive base substitutions in exon 55: a T-->G transversion at position 7875 of the ATM cDNA and a G-->C transversion at position 7876. These transversions were confirmed by polymerase chain reaction/primer-induced restriction analysis with CelII. The double base substitution results in an amino acid change of an aspartic acid to a glutamic acid at codon 2625 and of an alanine to a proline at codon 2626 of the ATM protein. Both amino acids are conserved between the ATM protein and its functional homolog, the Atm gene product in the mouse. Furthermore, the Chou-Fasman and Robson predictions both demonstrate a change in the secondary structure of the ATM protein carrying the D2625E/A2626P mutation. These findings suggest that the double base substitution in the ATM gene is a disease-causing mutation.

The Aircardi-Goutières syndrome: variable clinical expression in two siblings.

We report 2 siblings with the Aicardi-Goutières syndrome (encephalopathy, basal ganglia calcifications, and persistent cerebrospinal fluid pleiocytosis). The eldest sibling is severely retarded; his younger brother has only mild, slowly progressive neurological deficits. To our knowledge, such a striking difference in clinical expression has not been reported previously.

['Cerebral running nose': cerebrospinal rhinorrhea]. / 'Cerebrale loopneus': rhinorrhoea cerebrospinalis.

Cerebrospinal fluid rhinorrhoea was diagnosed in two patients, a man of 19 and a woman of 45 years old. This is a relatively rare phenomenon and clinically often difficult to differentiate from nasal secretions caused by a rhinopathy. Although cerebrospinal fluid (CSF) fistulae usually are of traumatic origin as in the first patient, they can also be caused by a congenital malformation as in the second one or by a condition with chronic increased intracranial pressure. With adequate treatment the prognosis is good. CSF can be identified very specifically by beta-transferrin determination.

Late-onset ataxia telangiectasia in two brothers presenting with juvenile resting tremor.

Two young adult brothers presented with a 5- to 6-Hz resting tremor of the upper limbs. Although ataxia was not unequivocally present and ocular telangiectasia was minimal, typical rearrangements of chromosomes 7 and 14, and increased alpha-feto-protein levels indicated the presence of ataxia telangiectasia (AT). Resting tremor as a predominating symptom in AT is uncommon and to our knowledge has not been described previously.

Folates: epileptogenic effects and enhancing effects on [3H]TBOB binding to the GABAA-receptor complex.

The biochemical mechanism responsible for the convulsive effects of folates was investigated. The epileptogenic effects of folates were determined in vivo by quantification of the seizures following intracortical application in rats. The rank order of epileptogenic effects is: folic acid greater than or equal to 5-HCO-H4 folate greater than H2 folate greater than 5-CH3-H4 folate. This sequence of epileptogenicity in vivo is compared to the rank order of the effects of folates on radioligand binding to the GABAA-receptor complex in vitro. The inhibitory potencies of folates on [3H]muscimol and [3H]diazepam bindings did not correlate with their epileptogenic effects. However, folates reverse the inhibiting effect of GABA on the binding of the cage convulsant [3H]TBOB [( 3H]t-butylbicycloorthobenzoate). The rank order of this in vitro effect (folic acid greater than 5-HCO-H4 folate greater than H2 folate = 5-CH3-H4 folate) resembles the rank order of epileptogenicity determined in vivo. A relationship between the in vivo and in vitro effects is therefore suggested.