[show abstract][hide abstract] ABSTRACT: Osteogenesis imperfecta (OI) is a genetic disorder of connective tissue characterized by bone fragility and alteration in synthesis and posttranslational modification of type I collagen. Autosomal dominant OI is caused by mutations in the genes (COL1A1 or COL1A2) encoding the chains of type I collagen. Bruck syndrome is a recessive disorder featuring congenital contractures in addition to bone fragility; Bruck syndrome type 2 is caused by mutations in PLOD2 encoding collagen lysyl hydroxylase, whereas Bruck syndrome type 1 has been mapped to chromosome 17, with evidence suggesting region 17p12, but the gene has remained elusive so far. Recently, the molecular spectrum of OI has been expanded with the description of the basis of a unique posttranslational modification of type I procollagen, that is, 3-prolyl-hydroxylation. Three proteins, cartilage-associated protein (CRTAP), prolyl-3-hydroxylase-1 (P3H1, encoded by the LEPRE1 gene), and the prolyl cis-trans isomerase cyclophilin-B (PPIB), form a complex that is required for fibrillar collagen 3-prolyl-hydroxylation, and mutations in each gene have been shown to cause recessive forms of OI. Since then, an additional putative collagen chaperone complex, composed of FKBP10 (also known as FKBP65) and SERPINH1 (also known as HSP47), also has been shown to be mutated in recessive OI. Here we describe five families with OI-like bone fragility in association with congenital contractures who all had FKBP10 mutations. Therefore, we conclude that FKBP10 mutations are a cause of recessive osteogenesis imperfecta and Bruck syndrome, possibly Bruck syndrome Type 1 since the location on chromosome 17 has not been definitely localized.
Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 03/2011; 26(3):666-72. · 6.04 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the genetic causes of idiopathic sporadic prenatal generalized edema.
In a series of 12 patients, in whom in utero generalized skin edema or hydrops fetalis had been diagnosed, we screened 3 lymphangiogenic genes, VEGFR3, FOXC2, and SOX18.
In 3 of the patients, we identified a mutation: 2 in VEGFR3 and 1 in FOXC2. Two of the mutations were de novo and one was either de novo or nonpenetrant inherited. In these patients, the generalized edema resorbed spontaneously, either in utero or after birth. In the 2 individuals with a VEGFR3 mutation, edema remained limited to lower limbs.
Mutations in the VEGFR3 and FOXC2 genes account for a subset of patients with unexplained in utero generalized subcutaneous edema and hydrops fetalis without family history of lymphedema. Lymphangiogenic genes should be screened for mutations in sporadic patients diagnosed with fetal edema.
The Journal of pediatrics 05/2009; 155(1):90-3. · 4.02 Impact Factor
[show abstract][hide abstract] ABSTRACT: We report on 11 patients from 8 families with a blepharophimosis and mental retardation syndrome (BMRS) phenotype. Using current nosology, five sporadic patients have Ohdo syndrome, associated with congenital hypothyroidism in two of them (thus also compatible with a diagnosis of Young-Simpson syndrome). In two affected sibs with milder phenotype, compensated hypothyroidism was demonstrated. In another family, an affected boy was born to the unaffected sister of a previously reported patient. Finally, in the last sibship, two affected boys in addition had severe microcephaly and neurological anomalies. A definitive clinical and etiologic classification of BMRS is lacking, but closer phenotypic analysis should lead to a more useful appraisal of the BMRS phenotype. We suggest discontinuing the systematic use of the term "Ohdo syndrome" when referring to patients with BMRS. We propose a classification of BMRS into five groups: (1) del(3p) syndrome, (possibly overlooked in older reports); (2) BMRS, Ohdo type, limited to the original patients of Ohdo; (3) BMRS SBBYS (Say-Barber/Biesecker/Young-Simpson) type, with distinctive dysmorphic features and inconstant anomalies including heart defect, optic atrophy, deafness, hypoplastic teeth, cleft palate, joint limitations, and hypothyroidism. BMRS type SBBYS is probably an etiologically heterogeneous phenotype, as AD and apparently AR forms exist; (4) BMRS, MKB (Maat-Kievit-Brunner) type, with coarse, triangular face, which is probably sex-linked; (5) BMRS V (Verloes) type, a probable new type with severe microcephaly, hypsarrhythmia, adducted thumbs, cleft palate, and abnormal genitalia, which is likely autosomal recessive. Types MKB and V are newly described here.
American Journal of Medical Genetics Part A 07/2006; 140(12):1285-96. · 2.30 Impact Factor
[show abstract][hide abstract] ABSTRACT: Baller-Gerold syndrome (BGS) is a rare autosomal recessive condition with radial aplasia/hypoplasia and craniosynostosis (OMIM 218600). Of >20 cases reported so far, a few appear atypical and have been reassigned to other nosologic entities, including Fanconi anaemia, Roberts SC phocomelia, and Pfeiffer syndromes after demonstration of corresponding cytogenetic or molecular abnormalities. Clinical overlap between BGS, Rothmund-Thomson syndrome (RTS), and RAPADILINO syndrome is noticeable. Because patients with RAPADILINO syndrome and a subset of patients with RTS have RECQL4 mutations, we reassessed two previously reported BGS families and found causal mutations in RECQL4 in both. In the first family, four affected offspring had craniosynostosis and radial defect and one of them developed poikiloderma. In this family, compound heterozygosity for a R1021W missense mutation and a g.2886delT frameshift mutation of exon 9 was found. In the second family, the affected male had craniosynostosis, radial ray defect, poikiloderma, and short stature. He had a homozygous splice site mutation (IVS17-2A>C). In both families, the affected offspring had craniosynostosis, radial defects, and growth retardation, and two developed poikiloderma. Our results confirm that BGS in a subgroup of patients is due to RECQL4 mutations and could be integrated into a clinical spectrum that encompasses RTS and RAPADILINO syndrome.
Journal of Medical Genetics 03/2006; 43(2):148-52. · 5.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cleft lip with or without cleft palate (CL/P) is one of the most common birth defects in the world. Prevalence varies between populations, with an average of 1/700. CL/P has a major clinical impact, requiring surgical, dental, orthodontic, speech, hearing and psychological management throughout childhood. The aetiology of CL/P is mostly unknown, and it is thought that both genetic and environmental factors play a role. Several causative genes for inherited syndromic forms of CL/P have been identified, and some recent studies have shown that these genes also contribute to the occurrence of isolated forms. Van der Woude syndrome (VWS) is one of the best models for non-syndromic CLP. It is an autosomal dominant disorder characterised by the presence of pits on the lower lip in addition to CL/P. Pits are the only feature distinguishing VWS from isolated clefts. Interestingly, in numerous VWS patients, the lip pits are very small and not readily diagnosed, thus mimicking isolated CL/P. Mutations in the IRF6 gene were shown to be the major genetic cause of VWS.'
We performed direct sequence analysis of IRF6 on samples from a large European cohort and identified mutations in 27 (80%) families. This shows that IRF6 is the major causative gene of VWS in Europe also. Moreover, it is the gene to study when a seemingly isolated CL/P patient has minor signs, such as lip pits, since the identification of a mutation in IRF6 is associated with an increase in the risk of having a child with CL/P from 4-6%, the risk of transmission of an isolated cleft, to 50%, the risk of transmission of a dominant Mendelian disorder like VWS. Moreover, we studied the association of isolated CL/P with the IRF6 locus using two variants in a set of 195 patients from Belgium. As in an American study, a clear association was observed. This suggests that IRF6 also contributes to the occurrence of sporadic, isolated CL/P, even if no mutation in the gene can be identified in such patients.
In conclusion, genes that are mutated in familial syndromic forms of CL/P may be predisposing genetic factors to sporadic isolated CL/P. Due to technological advances and the availability of the human genome sequence, we have now the opportunity to try and unravel the genetic factors behind the various forms of CL/P.
[show abstract][hide abstract] ABSTRACT: Cleft lip with or without cleft palate is the most frequent craniofacial malformation in humans ( approximately 1/700). Its etiology is multifactorial; some are a result of a genetic mutation, while others may be due to environmental factors, with genetic predisposition playing an important role. The prevalence varies widely between populations and the mode of inheritance remains controversial. The interferon regulatory factor-6 (IRF6) gene has been shown to harbor mutations in patients with van der Woude syndrome, a dominant form of clefts associated with small pits of the lower lip. Moreover IRF6 has been associated with nonsyndromic cleft of the palate (CL/P) in two separate studies. We investigated the role of IRF6 in a set of 195 trios from Belgium. Cleft occurred as an isolated feature. We studied association of the IRF6 locus using two variants: one in the IRF6 gene and the other 100 kpb 3' of the gene. Our independent study group confirms that the IRF6 locus is associated with nonsyndromic cleft lip with or without palate. This result, with previous studies performed in the United States and Italy, shows for the first time the implication of IRF6 in isolated CL/P in northern Europe. It is likely that association to this locus can be identified in various populations and that the IRF6 locus thus represents an important genetic modifier for this multifactorial malformation.
European Journal of HumanGenetics 12/2005; 13(11):1239-42. · 4.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: Follicular Lymphoma is a low grade malignancy of mature B-cells. The hallmark chromosome abnormality is the translocation t(14;18) which is observed in 70 - 80% of cases with a translocation t(3;14) present in a further 10%. Rarely both of these translocations, or one of their variants, may be present. These co-incident translocations usually involve different Ig loci or different Ig alleles. We present here a case of Follicular Lymphoma with leukemic presentation and a complex translocation involving the IgH, BCL2 and BCL6 loci. Double oncogene translocations to a single immunoglobulin locus are extremely rare in lymphomas with few cases described to date. To our knowledge this is the first reported case with a complex translocation involving these loci.
Leukemia and Lymphoma 11/2005; 46(10):1513-6. · 2.30 Impact Factor
[show abstract][hide abstract] ABSTRACT: We report on a fetus with multiple congenital anomalies detected at the prenatal ultrasound examination and a trisomy 6 mosaicism in the amniocytes. The pregnancy was interrupted in the 18th gestational week and the autopsy revealed malformations including cleft right hand, arthrogryposis and hypoplasia of the 4th digit of the left hand, syndactylies and overlapping toes, facial dysmorphism with hypertelorism and low-set ears, ventricular septum defect (VSD), intestinal malrotation and scoliosis. Trisomy 6 mosaicism was detected in cultured amniocytes (13.3%), confirmed in umbilical cord fibroblasts (40%) and by fluorescence in situ hybridization on other fetal tissues. Trisomy 6 mosaicism is a very rare finding with only eight cases previously reported to our best knowledge.
[show abstract][hide abstract] ABSTRACT: We present a case of de novo trisomy of distal 19q diagnosed prenatally by cytogenetics and FISH analysis. The autopsy performed after termination of the pregnancy showed major internal and external malformations that are associated with this chromosome abnormality.
[show abstract][hide abstract] ABSTRACT: A 31-year-old woman had encephalopathy, growth retardation, infantilism, ataxia, deafness, lactic acidosis, and increased signals of caudate and putamen on brain magnetic resonance imaging. Muscle biochemistry showed succinate:cytochrome c oxidoreductase (complex II-III) deficiency. Both clinical and biochemical abnormalities improved remarkably with coenzyme Q10 supplementation. Clinically, when taking 300mg coenzyme Q10 per day, she resumed walking, gained weight, underwent puberty, and grew 20cm between 24 and 29 years of age. Coenzyme Q10 was markedly decreased in cerebrospinal fluid, muscle, lymphoblasts, and fibroblasts, suggesting the diagnosis of primary coenzyme Q10 deficiency. An older sister has similar clinical course and biochemical abnormalities. These findings suggest that coenzyme Q10 deficiency can present as adult Leigh's syndrome.
Annals of Neurology 01/2003; 52(6):750-4. · 11.19 Impact Factor
[show abstract][hide abstract] ABSTRACT: Mutations in FOXL2, a forkhead transcription factor gene, have recently been shown to cause blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) types I and II, a rare genetic disorder. In BPES type I a complex eyelid malformation is associated with premature ovarian failure (POF), whereas in BPES type II the eyelid defect occurs as an isolated entity. In this study, we describe the identification of novel mutations in the FOXL2 gene in BPES types I and II families, in sporadic BPES patients, and in BPES families where the type could not be established. In 67% of the patients studied, we identified a mutation in the FOXL2 gene. In total, 21 mutations (17 of which are novel) and one microdeletion were identified. Thirteen of these FOXL2 mutations are unique. In this study, we demonstrate that there is a genotype--phenotype correlation for either types of BPES by the finding that mutations predicted to result in a truncated protein either lacking or containing the forkhead domain lead to BPES type I. In contrast, duplications within or downstream of the forkhead domain, and a frameshift downstream of them, all predicted to result in an extended protein, cause BPES type II. In addition, in 30 unrelated patients with isolated POF no causal mutations were identified in FOXL2. Our study provides further evidence that FOXL2 haploinsufficiency may cause BPES types I and II by the effect of a null allele and a hypomorphic allele, respectively. Furthermore, we propose that in a fraction of the BPES patients the genetic defect does not reside within the coding region of the FOXL2 gene and may be caused by a position effect.
Human Molecular Genetics 08/2001; 10(15):1591-600. · 7.69 Impact Factor
[show abstract][hide abstract] ABSTRACT: In South Belgium (Wallonia), the 'triple test' was introduced in 1990-1991, and is nowadays a widely accepted screening method for assessment of trisomy 21 risk in pregnancy. The 'triple test' is not regulated and can be freely performed by any biomedical lab, making epidemiological data unavailable. By contrast, cytogenetic investigations are limited to a few genetic centres, and accurate statistics can be easily built from their files. During the period 1984-1989, a total of 244 trisomy 21 (1/876 pregnancies) were diagnosed in the Genetic Centres of Liège and Loverval, 42 (17%) of them prenatally. During the period 1993-1998, 294 trisomy 21 (1/704 pregnancies) were observed, 165 (56%) of which prenatally, and more than 90% of affected pregnancies were terminated. Even after correction for late foetal loss of trisomic foetuses, the difference is highly significant, and corresponds to a theoretical shift in the incidence of trisomy 21 at birth from 1/794 to 1/1606. As no remarkable progress occurred in other non-invasive prenatal screening procedures or general health care policies in Belgium, the most reasonable explanation is the use on a large scale of triple test by pregnant women, and the election of termination for most affected pregnancies.
European Journal of HumanGenetics 02/2001; 9(1):1-4. · 4.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: We present the clinical, pathological, biochemical, and molecular results on an infant girl with long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency and data on her deceased elder brother for whom this condition was retrospectively diagnosed. Clinical signs were liver enlargement and elevated liver enzymes, failure to thrive, and neurological disease (coma, seizures) triggered by an infectious stress. In the second child hepatic failure and status epilepticus developed during the onset of a rotavirus gastroenteritis. A barbituric coma was induced, but hypotonia and lack of eye pursuit persisted after suppression of antiepileptic drugs. She ultimately died of heart failure. Unlike previously reported cases, both of these patients had early-onset cirrhosis, and severe neurological disease was observed in the second child. CONCLUSION: Liver cirrhosis and brain damage may be underestimated in cases of long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency and may occur early in life.
European Journal of Pediatrics 01/2000; 159(1-2):108-12. · 1.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: Three unrelated patients with congenital arthrogryposis and brittle bones, the main neonatal signs of Bruck syndrome, are presented. In infancy and early childhood recurrent fractures of ribs and long bones and persistent Wormian bones in the calvarium are reminiscent of osteogenesis imperfecta (OI) even with white sclerae, normal dental quality and normal hearing as important clinical negatives. The diagnosis was made before two years of age in two, and in adolescence in the third patient. The latter's radiologically documented long-term natural course reveals slow progressivity of osteopenia and growth deficiency, worsening tendon contractures and pterygia in addition to increasing spine and pelvis deformation. Mental development remains normal. Bruck syndrome is monogenic and probably due to homozygosity of an as yet unidentified gene. As no alteration in the collagens I and III is detected and molecular screening reveals no mutation in the COL1A1 and COL1A2 genes, the pathogenesis of this severe disorder of connective tissue remains largely unknown.