Encephalopathy caused by novel mutations in the CMP-sialic acid transporter, SLC35A1.

Transport of activated nucleotide-sugars into the Golgi is critical for proper glycosylation and mutations in these transporters cause a group of rare genetic disorders termed congenital disorders of glycosylation. We performed exome sequencing on an individual with a profound neurological presentation and identified rare compound heterozygous mutations, p.Thr156Arg and p.Glu196Lys, in the CMP-sialic acid transporter, SLC35A1. Patient primary fibroblasts and serum showed a considerable decrease in the amount of N- and O-glycans terminating in sialic acid. Direct measurement of CMP-sialic acid transport into the Golgi showed a substantial decrease in overall rate of transport. Here we report the identification of the third patient with CMP-sialic acid transporter deficiency, who presented with severe neurological phenotype, but without hematological abnormalities.

LIS1-associated classic lissencephaly: A retrospective, multicenter survey of the epileptogenic phenotype and response to antiepileptic drugs.

BACKGROUND: Patients with LIS1-associated classic lissencephaly typically present with severe psychomotor retardation and drug-resistant epilepsy within the first year. AIM: To analyze the epileptogenic phenotype and response to antiepileptic therapy in LIS1-associated classic lissencephaly. METHOD: Retrospective evaluation of 22 patients (8 months-24 years) with genetically and radiologically confirmed LIS1-associated classic lissencephaly in 16 study centers. RESULTS: All patients in our cohort developed drug-resistant epilepsy. In 82% onset of seizures was noted within the first six months of life, most frequently with infantile spasms. Later in infancy the epileptogentic phenotype became more variable and included different forms of focal seizures as well generalized as tonic-clonic seizures, with generalized tonic-clonic seizures being the predominant type. Lamotrigine and valproate were rated most successful with good or partial response rates in 88-100% of the patients. Both were evaluated significantly better than levetiracetam (p<0.05) and sulthiame (p<0.01) in the neuropediatric assessment and better than levetiracetam, sulthiame (p<0.05) and topiramate (p<0.01) in the family survey. Phenobarbital and vigabatrin achieved good or partial response in 62-83% of the patients. CONCLUSION: Our findings suggest that patients with LIS1-associated lissencephaly might benefit most from lamotrigine, valproate, vigabatrin or phenobarbital.

Comparison of gene expression profiling between malignant and normal plasma cells with oligonucleotide arrays.

The DNA microarray technology enables the identification of the large number of genes involved in the complex deregulation of cell homeostasis taking place in cancer. Using Affymetrix microarrays, we have compared the gene expression profiles of highly purified malignant plasma cells from nine patients with multiple myeloma (MM) and eight myeloma cell lines to those of highly purified nonmalignant plasma cells (eight samples) obtained by in vitro differentiation of peripheral blood B cells. Two unsupervised clustering algorithms classified these 25 samples into two distinct clusters: a malignant plasma cell cluster and a normal plasma cell cluster. Two hundred and fifty genes were significantly up-regulated and 159 down-regulated in malignant plasma samples compared to normal plasma samples. For some of these genes, an overexpression or downregulation of the encoded protein was confirmed (cyclin D1, c-myc, BMI-1, cystatin c, SPARC, RB). Two genes overexpressed in myeloma cells (ABL and cystathionine beta synthase) code for enzymes that could be a therapeutic target with specific drugs. These data provide a new insight into the understanding of myeloma disease and prefigure that the development of DNA microarray could help to develop an 'à la carte' treatment in cancer disease.