Search PubMed⌕ Search

Biomedical subjects

Jean-Pierre Fryns

Publications and source records attributed to Jean-Pierre Fryns.

99 records · Page 6Linked to original sources
PubMed2002

Pathogenic mutations and rare variants of the APC gene identified in 75 Belgian patients with familial adenomatous polyposis by fluorescent enzymatic mutation detection (EMD).

Familial adenomatous polyposis (FAP) is a dominant inherited colorectal cancer syndrome which is caused by germline mutations in the adenomatous polyposis coli (APC) gene. Enzymatic mutation detection (EMD) has potential advantages over the standard protein truncation test (PTT) that is currently used in screening the APC gene for mutations. First we wanted to validate the EMD technique in comparison to PTT. Secondly, we wanted to develop an efficient working protocol for EMD screening of APC. Seventy-five unrelated patients were screened for mutations. All mutations that had previously been detected by PTT were also identified by EMD; the sizes of the cleavage fragments were as expected according to the position of the mutations within the amplicons. A new screening strategy based on EMD allows the analysis of the APC gene in 31 overlapping PCR fragments. In total, EMD efficiently detected the 26 truncating mutations in this series. In addition, two rare variants were also detected: the first is the typical Ashkenazi missense mutation I1307K while the second variant, E1317Q, has been identifed in Belgian patients and controls, and should no longer be considered as a pathogenic mutation, but rather classified as a polymorphism.

Adenomatous Polyposis Coli↗
PubMed2002

Coping with twins discordant for intellectual disabilities: the mothers' view.

In this exploratory study of 15 families with a twin-pair, of which one has an intellectual disability, the Nijmegen Questionnaire on Childrearing Situations (NQCS) was used to ask mothers about their perceptions and experiences of parenting. An interview with the mothers was done to understand the initial stages of coping with this double problem: educating a twin-pair and a child with an intellectual disability. Four groups of mothers were identified, depending on whether they accepted the intellectual disability of their child and/or whether they perceived their children as a twin-pair or not. Finally, some critical questions for further research and management were formulated.

Adaptation, Psychological↗
PubMed2002

The East Flanders Prospective Twin Survey (EFPTS).

The East Flanders Prospective Twin Survey (EFPTS) is a registry of multiple births in the province of East-Flanders, Belgium. It has several unique features: it is population-based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are ascertained at birth; basic perinatal data are recorded; chorion type and zygosity are established; and since 1969 placental biopsies have been taken and frozen at -20 degrees C for later determination of genetic markers. The EFPTS is the only large register that includes placental data and allows differentiation of three subtypes of monozygotic (MZ) twins based on the time of the initial zygotic division: the dichorionic-diamnionic pairs (early, before the fourth day after fertilisation), the monochorionic-diamnionic pairs (intermediate, between the fourth and the seventh day post fertilisation), and the monochorionic-monoamnionic pairs (late, after the eight day post fertilisation). This added a new dimension to didymology (the science of twins; delta iota delta upsilon mu omicron zeta = twins): the timing of twinning. Studies can be initiated on primary biases, those originating "in utero". Such studies may throw new light on the controversy over the validity of the classic twin method, the consequences of early embryological events (before and just after implantation of the embryo), the origin of congenital malformations, the sex proportion of multiples, the gene-environment interactions as far as intrauterine environment is concerned, to name but a few.

Belgium↗
PubMedDate not supplied

Interstitial 6q deletion: clinical and array CGH characterisation of a new patient.

We report on a patient with an interstitial 6q deletion presenting with moderate mental retardation, persisting hypotonia, facial dysmorphism, but no internal malformations. Standard cytogenetic analysis identified a de novo interstitial 6q deletion. Molecular karyotyping using a 1 Mb array estimated the size of the deletion at approximately 14 Mb encompassing band q16 of chromosome 6. This case report illustrates how the molecular delineation enables improved genotype-phenotype correlations of chromosomal abnormalities to be made and may improve medical care and genetic counselling in individuals with chromosomal imbalances.

Child, Preschool↗
PubMedDate not supplied

Tetrasomy 12pter-12p13.31 in a girl with partial Pallister-Killian syndrome phenotype.

A dysmorphic patient was shown to carry a small supernumerary marker chromosome. Multicolor, centromere-multicolor and regular FISH experiments proved the marker to be an analphoid 12pter derived isochromosome. Microdissection of the marker followed by reverse painting and array CGH analysis showed that the isochromosome contains approximately 6 Mb of 12pter-12p13.31 derived sequence. This is only the second report of a marker with a neocentromere 12pter and the molecular fine mapping of the duplicated region further refines the 12p region defining the Pallister-Killian syndrome phenotype. In addition, we show the feasibility of using microdissected chromosomes or chromosomal fragments to molecularly map the chromosomal breakpoints on array CGH. This technology may aid in the identification of chromosomal translocation breakpoints.

Abnormalities, Multiple↗
PubMedDate not supplied

Trisomy of chromosome 16p13.3 due to an unbalanced insertional translocation into chromosome 22p13.

A dysmorphic boy with severe mental retardation was found on array CGH to have an insertional translocation of chromosome 16p13.3 into the short arm of chromosome 22, karyotype 46,XY,.ish der(22),ins(22;16)(p13;p13.3p13.3) de novo. His clinical features overlap with the reported cases of 'duplication 16p' syndrome, namely a round face, hypertelorism, a long philtrum, micrognathia, a thin upper lip, a posterior cleft palate and low set, simple ears, clubbed feet, severe developmental delay, psychomotor retardation and seizures. This 4-year boy with trisomy 16p13.3 has the smallest duplication reported of this critical region, which could not be detected without array CGH. The maximal duplicated region is gene rich and contains about 80 genes and/or candidate genes. Assignment of the genes that contribute to the observed phenotype awaits the characterisation of other patients with small duplications in this region.

Abnormalities, Multiple↗
PubMedDate not supplied

Speech and language in Wolf-Hirschhorn syndrome: a case-study.

UNLABELLED: Wolf-Hirschhorn syndrome (WHS), a condition resulting from a distal deletion of the short arm of chromosome 4, is usually associated with a severe phenotypic expression including multiple malformations, delayed psychomotor development, and profound learning disabilities. As far as communicative development is concerned, speech is usually absent and comprehension is limited to simple orders or to a specific context. There is some suggestion, however, that the developmental outcome in WHS depends on deletion size. This paper reports on an individual with WHS illustrating that a smaller deletion may result in a milder phenotype with respect to communicative abilities. This 10-year-old girl developed speech and language to a considerable degree. Although most children with this syndrome are severely limited in communicative abilities, the school-based speech-language pathologist working with a special education caseload may encounter WHS children with smaller deletions (and thus less severe phenotypes) who may profit from speech language pathology services. LEARNING OUTCOMES: The reader will learn about the genetics, incidence, and clinical characteristics of Wolf-Hirschhorn syndrome, and about the communicative abilities and genotype/phenotype correlations in children with this syndrome.

Carrier Proteins↗