Jean-Pierre Frijns

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A male patient, who had intra-uterine growth retardation, a low birth weight and hypotonia due to a chromosome 2q33.1 deletion, is described. At the age of 20 years, he displays short stature, microcephaly, a high forehead, microstomia, large teeth and is hypertonic. He is severely mentally retarded, has not developed speech, is hyperactive, anxious and at(More)
OBJECTIVE To test the hypothesis that patients with advanced maternal age (AMA) have a higher implantation rate (IR) after embryo transfer of embryos with a normal chromosomal pattern for the chromosomes studied with preimplantation genetic screening (PGS) compared with patients who had an embryo transfer without PGS. DESIGN Prospective randomized(More)
BACKGROUND Ring chromosome 20 syndrome is a rare chromosomal disorder. METHODS In six patients, we focused on the presenting epileptic phenotype, the behavioral and mental problems and the relationship between the ratio of mosaicism and the age at onset of the epilepsy. RESULTS All patients presented with pharmacoresistant frontal lobe complex partial(More)
In a cohort of 103 females clinically diagnosed with Rett syndrome (RTT), 91 had a detectable MECP2 mutation. Emphasis on details of natural history facilitated grouping of females with the same MECP2 mutation and the development of so-called disorder profiles. Some examples of disorder profiles of different recurrent MECP2 mutations are discussed. RTT(More)
Costello syndrome is a mental retardation syndrome characterized by high birth weight, postnatal growth retardation, coarse face, loose skin, cardiovascular problems, and tumor predisposition. De novo heterozygous missense mutations in HRAS codon 12 and 13 disturbing the intrinsic GTP hydrolysis cause Costello syndrome. We report a patient with typical(More)
Rett syndrome (RTT; OMIM 312750) is an X-linked dominant neurodevelopmental disorder leading to cognitive and motor impairment, epilepsy, and autonomic dysfunction in females. Since the discovery that RTT is caused by mutations in MECP2, large retrospective genotype-phenotype correlation studies have been performed. A number of general genotype-phenotype(More)
OBJECTIVE To study the occurrence of congenital aural atresia in patients with a deletion of the long arm of chromosome 18 (18q- deletion or de Grouchy syndrome). STUDY DESIGN AND PATIENTS This retrospective study presents an overview of the otologic findings in 33 Dutch and Belgian patients with a deletion of 18q. MATERIALS AND METHODS Detailed(More)
Holt-Oram syndrome (MIM #142900) is an autosomal-dominant disorder characterized by radial ray deformities of the upper limb associated with cardiac septation and/or conduction defects. The disorder is caused by mutations in the transcription factor TBX5. Several studies report a rather low detection rate (range, 22-35%) of TBX5 mutations in patients with a(More)
PURPOSE Prader-Willi syndrome is associated with hypogonadism. Cryptorchidism is found in 93% of cases and considered a phenotypic criterion. Men with Prader-Willi syndrome are thought to be infertile. To study the fertility probability in boys with Prader-Willi syndrome we analyzed testicular histology in 8 prepubertal boys and 1 man. MATERIALS AND(More)
Mutations in the methyl-CpG-binding protein 2 (MECP2) gene located on Xq28, cause Rett syndrome (RTT) in female patients. Meanwhile, nonmosaic MECP2 mutations unknown in girls have been found in an increasing number of male patients with a normal 46, XY karyotype. They can cause a broad spectrum of neurodevelopmental disorders which often show a combination(More)