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Koen Devriendt

Publications and source records attributed to Koen Devriendt.

44 records · Page 3Linked to original sources
PubMed2002

Glypican 1 gene: good candidate for brachydactyly type E.

In this report, we describe two siblings, a brother and a sister, with mental retardation and limb abnormalities (brachymetacarpy and brachymetatarsy in the brother and clinodactyly in his sister). Fluorescent in situ hybridization analysis (FISH) using subtelomeric probes proved that the patients carried an unbalanced subtelomeric rearrangement with 2qter deletion involving the Glypican 1 gene. Given the expression pattern in the developing limb bud, Glypican 1 gene represents a good candidate for brachydactyly E.

Chromosome Deletion↗
PubMed2002

Progressive AV-block and anomalous venous return among cardiac anomalies associated with two novel missense mutations in the CSX/NKX2-5 gene.

Non-syndromic cardiac septation defects are common, yet the causative factors remain largely uncharacterised. Septation defects are an integral part of many syndromes, some of which are associated with chromosomal alterations. For the majority, the physiopathogenesis is believed to be multi-factorial, hindering the identification of causative factors. Ten mutations in the gene encoding the transcription factor CSX/NKX2-5 have been described in individuals with ASD and/or atrioventricular conduction defects. In addition, several other cardiac abnormalities were observed, yet the mildest forms are reminiscent of non-syndromic septation defects. The CSX/NKX2-5 gene is thus a good candidate for various cardiopathies. We have collected two families with inherited predisposition to cardiac abnormalities. Some members of the families presented ASD and AV block. In both families a novel CSX/NKX2-5 mutation was identified in the homeodomain. Variable expressivity in the phenotype was observed in both families. Importantly, mutation carriers did not present any symptoms at young age. In addition, anomalous venous return, a phenotype not previously associated to CSX/NKX2-5 mutations, was observed in one of the families. We also screened the CSX/NKX2-5 gene in sporadic and familial cases of other cardiopathies. As additional mutations were not found, substitutions in CSX/NKX2-5 gene seem to be a rare cause of cardiopathies without conduction defect.

Amino Acid Sequence↗
PubMed2002

Human piebaldism: six novel mutations of the proto-oncogene KIT.

Human piebaldism is a rare autosomal dominant disorder that comprises congenital patchy depigmentation of the scalp, forehead, trunk and limbs. It is caused by mutations in the cell-surface receptor tyrosine kinase gene (KIT, also c-kit). We screened three families and three isolated cases of piebaldism from different countries for mutations in the KIT gene using automated sequencing methods. We report six novel KIT point mutations: three missense (C788R, W835R, P869S) at highly conserved amino acid sites; one nonsense (Q347X) that results in termination of translation of the KIT gene in exon 6; and two splice site nucleotide substitutions (IVS13+2T>G, IVS17-1G>A) that are predicted to impair normal splicing. These mutations were not detected in over 100 normal individuals and are likely to be the cause of piebaldism in our subjects.

Adult↗
PubMed2002

VATER--tibia aplasia association: report on two patients.

We report two patients with oesophageal atresia, tracheo-oesophageal fistula and unilateral tibial aplasia. The karyotype in both patients was normal and both cases were sporadic. The congenital defects of the children can be regarded as an uncommon variant of VA(C)TER(L) association. Recently Basel and Goldblatt [(2000) Clin Dysmorphol 9:205-208] reported a similar patient with a VATER-tibia aplasia association.

Abnormalities, Multiple↗
PubMed2002

Genes in a refined Smith-Magenis syndrome critical deletion interval on chromosome 17p11.2 and the syntenic region of the mouse.

Smith-Magenis syndrome (SMS) is a multiple congenital anomaly/mental retardation syndrome associated with behavioral abnormalities and sleep disturbance. Most patients have the same approximately 4 Mb interstitial genomic deletion within chromosome 17p11.2. To investigate the molecular bases of the SMS phenotype, we constructed BAC/PAC contigs covering the SMS common deletion interval and its syntenic region on mouse chromosome 11. Comparative genome analysis reveals the absence of all three approximately 200-kb SMS-REP low-copy repeats in the mouse and indicates that the evolution of SMS-REPs was accompanied by transposition of adjacent genes. Physical and genetic map comparisons in humans reveal reduced recombination in both sexes. Moreover, by examining the deleted regions in SMS patients with unusual-sized deletions, we refined the minimal Smith-Magenis critical region (SMCR) to an approximately 1.1-Mb genomic interval that is syntenic to an approxiamtely 1.0-Mb region in the mouse. Genes within the SMCR and its mouse syntenic region were identified by homology searches and by gene prediction programs, and their gene structures and expression profiles were characterized. In addition to 12 genes previously mapped, we identified 8 new genes and 10 predicted genes in the SMCR. In the mouse syntenic region of the human SMCR, 16 genes and 6 predicted genes were identified. The SMCR is highly conserved between humans and mice, including 19 genes with the same gene order and orientation. Our findings will facilitate both the identification of gene(s) responsible for the SMS phenotype and the engineering of an SMS mouse model.

Abnormalities, Multiple↗
PubMedDate not supplied

Chromosome 10p deletion in a patient with hypoparathyroidism, severe mental retardation, autism and basal ganglia calcifications.

Chromosome 10p terminal deletions have been associated with a DiGeorge like phenotype. Haploinsufficiency of the region 10p14-pter, results in hypoparathyroidism, sensorineural deafness, renal anomaly, that is the triad that features the HDR syndrome. Van Esch (2000) identified in a HDR patient, within a 200 kb critical region, the GATA3 gene, a transcription factor involved in the embryonic development of the parathyroids, auditory system and kidneys. We describe a new male patient, 33-year-old, with 10p partial deletion affected by hypocalcemia, basal ganglia calcifications and a severe autistic syndrome associated with mental retardation. Neurologically he presented severe impairment of language, hypotonia, clumsiness and a postural dystonic attitude. A peripheral involvement of auditory pathways was documented by auditory evoked potentials alterations. CT scan documented basal ganglia calcifications. Hyperintensity of the lentiform nuclei was evident at the MRI examination. Renal ultrasound scan was normal. Haploinsufficiency for GATA3 gene was documented with FISH analysis using cosmid clone 1.2. Phenotypic spectrum observed in del (10p) is more severe than the classical DGS spectrum. GATA3 has been found to regulate the development of serotoninergic neurons. A serotoninergic dysfunction may be linked with autism in this patient.

Abnormalities, Multiple↗