26
|
Rabès JP, Varret M, Devillers M, Aegerter P, Villéger L, Krempf M, Junien C, Boileau C. R3531C mutation in the apolipoprotein B gene is not sufficient to cause hypercholesterolemia. Arterioscler Thromb Vasc Biol 2000; 20:E76-82. [PMID: 11031227 DOI: 10.1161/01.atv.20.10.e76] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Familial hypercholesterolemia and familial ligand-defective apolipoprotein B-100 (FDB) are dominantly inherited disorders leading to impaired low-density lipoprotein receptor (LDLR) and apolipoprotein B-100 (APOB) interaction, plasma LDL elevation, and hypercholesterolemia. We previously identified the first French FDB-R3531C proband, a woman with very high total cholesterol, in a group of type IIa hypercholesterolemic families. We report here the investigation of her family at large that revealed the total absence of cosegregation with hypercholesterolemia. Six of the 10 subjects heterozygous for the R3531C mutation had plasma cholesterol lower than the 97.5th percentile for their age and gender, and mean cholesterol levels were not significantly different between affected and unaffected persons. Furthermore, 2 family members with similar high LDL-cholesterol levels were not carriers of the R3531C substitution, suggesting the implication of another mutation. Segregation analysis of the LDLR gene revealed statistically significant genetic linkage with hypercholesterolemia, and analysis of the proband LDLR gene led to the identification of the 664 proline to leucine defective mutation and its detection in all 6 hypercholesterolemic-related members of this family. Therefore, our results show that the family presents with familial hypercholesterolemia and give evidence that the R3531C substitution in the APOB gene is not an allelic variant leading to FDB. Furthermore, thorough analysis of our data suggests that the APOB-R3531C mutation enhances the hypercholesterolemic effect of the LDLR-P664L defect, suggesting that it is a susceptibility mutation.
Collapse
|
27
|
Dereure O, Savoy D, Doz F, Junien C, Guilhou JJ. Multiple acral fibromas in a patient with familial retinoblastoma: a cutaneous marker of tumour-suppressor gene germline mutation? Br J Dermatol 2000; 143:856-9. [PMID: 11069472 DOI: 10.1046/j.1365-2133.2000.03790.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report a 40-year-old patient with familial retinoblastoma also affecting his elder son, who developed multiple fibromas on the periungual or subungual areas of all the fingers. Molecular analysis disclosed a loss of heterozygosity for the RB1 gene in the larger tumour, with disappearance of the normal allele and persistence of the mutated allele only. The similarity of this observation with distal fibrous tumours encountered in other diseases with germline mutations of tumour-suppressor genes such as neurofibromatosis type 1, tuberous sclerosis and multiple endocrine neoplasia type 1 led to the hypothesis that multiple acral benign tumours with a fibrous component might be a cutaneous marker of tumour suppressor gene germline mutation with low sensitivity but high specificity.
Collapse
|
28
|
Marquis E, Le Monnier de Gouville I, Bouvattier C, Robert JJ, Junien C, Charron D, Hors J, Diatloff-Zito C. HLA-DRB1 and DQB1 genotypes in patients with insulin-dependent neonatal diabetes mellitus. A study of 13 cases. TISSUE ANTIGENS 2000; 56:217-22. [PMID: 11034557 DOI: 10.1034/j.1399-0039.2000.560303.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Insulin-dependent neonatal diabetes mellitus (NDM) is a rare form of diabetes with a heterogeneous genetic background. The HLA-DRB1 and DQB1 genotypes were determined for 13 patients with NDM, from 9 unrelated families. Four patients had permanent NDM (PNDM) and 9 patients had transient NDM (TNDM). No excess of HLA susceptibility markers for type 1 diabetes (IDDM) was observed in this series of patients, whatever the forms of diabetes PNDM or TNDM. Paternal isodisomy of chromosome 6 was observed in two TNDM cases. These observations are consistent with the current hypothesis that there is a recessive susceptibility gene, at least in the transient form of the disease, unlinked to the MHC locus on chromosome 6. Although established in a short series, our results do not support an additive role of IDDM1 in the progression of the disease.
Collapse
|
29
|
Saint-Jore B, Varret M, Dachet C, Rabès JP, Devillers M, Erlich D, Blanchard P, Krempf M, Mathé D, Chanu B, Jacotot B, Farnier M, Bonaïti-Péllié C, Junien C, Boileau C. Autosomal dominant type IIa hypercholesterolemia: evaluation of the respective contributions of LDLR and APOB gene defects as well as a third major group of defects. Eur J Hum Genet 2000; 8:621-30. [PMID: 10952765 DOI: 10.1038/sj.ejhg.5200516] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Autosomal dominant type IIa hypercholesterolaemia (ADH) is characterised by an elevation of total plasma cholesterol associated with increased LDL particles. Numerous different molecular defects have been identified in the LDL receptor (LDLR) and few specific mutations in the apolipoprotein B (APOB) gene resulting in familial hypercholesterolaemia and familial defective apoB-100 respectively. To estimate the respective contribution of LDLR, APOB and other gene defects in this disease, we studied 33 well characterised French families diagnosed over at least three generations with ADH through the candidate gene approach. An estimation of the proportions performed with the HOMOG3R program showed that an LDLR gene defect was involved in approximately 50% of the families (P = 0.001). On the other hand, the estimated contribution of an APOB gene defect was only 15%. This low estimation of ADH due to an APOB gene defect is further strengthened by the existence of only two probands carrying the APOB (R3500Q) mutation in the sample. More importantly and surprisingly, 35% of the families in the sample were estimated to be linked to neither LDLR nor APOB genes. These data were confirmed by the exclusion of both genes through direct haplotyping in three families. Our results demonstrate that the relative contributions of LDLR and APOB gene defects to the disease are very different. Furthermore, our results also show that genetic heterogeneity is, generally, underestimated in ADH, and that at least three major groups of defects are involved. At this point, the contribution of the recently mapped FH3 gene to ADH cannot be assessed nor its importance in the group of 'non LDLR/non APOB' families.
Collapse
|
30
|
Rabès JP, Varret M, Saint-Jore B, Erlich D, Jondeau G, Krempf M, Giraudet P, Junien C, Boileau C. Familial ligand-defective apolipoprotein B-100: simultaneous detection of the ARG3500-->GLN and ARG3531-->CYS mutations in a French population. Hum Mutat 2000; 10:160-3. [PMID: 9259199 DOI: 10.1002/(sici)1098-1004(1997)10:2<160::aid-humu8>3.0.co;2-o] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Familial ligand-defective apolipoprotein B-100 (FDB) is an autosomal dominant disorder leading to plasma LDL cholesterol elevation and coronary artery disease (CAD). Two specific mutations in the APOB gene--R3500Q and R3531C--induce FDB. We report an original method to detect both mutations simultaneously, based upon PCR-mediated, site-directed mutagenesis and double restriction of a unique PCR product. With this method we have investigated the prevalence of these mutations in 1,040 French patients. The R3500Q mutation was found in five probands. Genotypes were determined for 10 APOB polymorphic markers and were consistent with the common European ancestral haplotype previously reported. The only exception was one FDB proband who did not harbor the 48 repeat allele of the 3'HVR. Additionally, the first two R3531C mutations were identified in French probands. Genotypes were consistent with a previously reported haplotype, suggesting that this is another mutation of European ancestry.
Collapse
|
31
|
Gallou C, Joly D, Méjean A, Staroz F, Martin N, Tarlet G, Orfanelli MT, Bouvier R, Droz D, Chrétien Y, Maréchal JM, Richard S, Junien C, Béroud C. Mutations of the VHL gene in sporadic renal cell carcinoma: definition of a risk factor for VHL patients to develop an RCC. Hum Mutat 2000; 13:464-75. [PMID: 10408776 DOI: 10.1002/(sici)1098-1004(1999)13:6<464::aid-humu6>3.0.co;2-a] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To investigate the nature of somatic von Hippel-Lindau (VHL) mutations, we analyzed 173 primary sporadic human renal cell carcinomas for mutations of the VHL tumor suppressor gene, using polymerase chain reaction (PCR) and single-strand conformational polymorphism analysis (SSCP) of DNA. We detected abnormal SSCP pattern in 73 samples. After sequencing, we identified microdeletions in 58% of cases, microinsertions in 17%, nonsense mutations in 8%, and missense mutations in 17%. Among these mutations, 50% correspond to new mutations. VHL mutations were found only in the nonpapillary renal cell carcinoma (RCC) subtype, as previously reported. To compare somatic and germline mutations, we used the VHL database, which includes 507 mutations. The study of mutational events revealed a significant difference between somatic and germline mutations with mutations leading to truncated proteins observed in 78% of somatic mutations vs only 37% in germline mutations (P < 0.001). We postulated that a specific pattern of VHL mutations is associated with sporadic RCC. This pattern corresponds to mutations leading mainly to truncated proteins with few specific missense mutations. We then analyzed the occurrence of RCC in VHL families, based on the nature of mutations. We observed RCC in at least one member of the VHL families in 77% of cases with mutations leading to truncated proteins versus 55% in cases with missense mutations (P < 0.05). Thus, mutations resulting in truncated proteins may lead to a higher risk of RCC in VHL patients.
Collapse
|
32
|
Seznec H, Lia-Baldini AS, Duros C, Fouquet C, Lacroix C, Hofmann-Radvanyi H, Junien C, Gourdon G. Transgenic mice carrying large human genomic sequences with expanded CTG repeat mimic closely the DM CTG repeat intergenerational and somatic instability. Hum Mol Genet 2000; 9:1185-94. [PMID: 10767343 DOI: 10.1093/hmg/9.8.1185] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Myotonic dystrophy (DM) is caused by a CTG repeat expansion in the 3'UTR of the DM protein kinase (DMPK) gene. A very high level of instability is observed through successive generations and the size of the repeat is generally correlated with the severity of the disease and with age at onset. Furthermore, tissues from DM patients exhibit somatic mosaicism that increases with age. We generated transgenic mice carrying large human genomic sequences with 20, 55 or >300 CTG, cloned from patients from the same affected DM family. Using large human flanking sequences and a large amplification, we demonstrate that the intergenerational CTG repeat instability is reproduced in mice, with a strong bias towards expansions and with the same sex- and size-dependent characteristics as in humans. Moreover, a high level of instability, increasing with age, can be observed in tissues and in sperm. Although we did not observe dramatic expansions (or 'big jumps' over several hundred CTG repeats) as in congenital forms of DM, our model carrying >300 CTG is the first to show instability so close to the human DM situation. Our three models carrying different sizes of CTG repeat provide insight on the different factors modulating the CTG repeat instability.
Collapse
|
33
|
Abstract
Congenital hyperinsulinism (HI) is a clinically and genetically heterogeneous entity. The clinical heterogeneity is manifested by severity ranging from extremely severe, life threatening disease to very mild clinical symptoms, which may even be difficult to identify. Furthermore, clinical responsiveness to medical and surgical management is extremely variable. Recent discoveries have begun to clarify the molecular aetiology of this disease and thus the mechanisms responsible for this clinical heterogeneity are becoming more clear. Mutations in 4 different genes have been identified in patients with this clinical syndrome. Most cases are caused by mutations in either of the 2 subunits of the beta cell ATP sensitive K(+) channel (K(ATP)), whereas others are caused by mutations in the beta cell enzymes glucokinase and glutamate dehydrogenase. However, for as many as 50% of the cases, no genetic aetiology has yet been determined. The study of the genetics of this disease has provided important new information about beta cell physiology. Although the clinical ramifications of these findings are still limited, in some situations genetic studies might greatly aid in patient management.
Collapse
|
34
|
Béroud C, Collod-Béroud G, Boileau C, Soussi T, Junien C. UMD (Universal mutation database): a generic software to build and analyze locus-specific databases. Hum Mutat 2000. [PMID: 10612827 DOI: 10.1002/(sici)1098-1004(200001)15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The human genome is thought to contain about 80,000 genes and presently only 3,000 are known to be implicated in genetic diseases. In the near future, the entire sequence of the human genome will be available and the development of new methods for point mutation detection will lead to a huge increase in the identification of genes and their mutations associated with genetic diseases as well as cancers, which is growing in frequency in industrial states. The collection of these mutations will be critical for researchers and clinicians to establish genotype/phenotype correlations. Other fields such as molecular epidemiology will also be developed using these new data. Consequently, the future lies not in simple repositories of locus-specific mutations but in dynamic databases linked to various computerized tools for their analysis and that can be directly queried on-line. To meet this goal, we devised a generic software called UMD (Universal Mutation Database). It was developed as a generic software to create locus-specific databases (LSDBs) with the 4(th) Dimension(R) package from ACI. This software includes an optimized structure to assist and secure data entry and to allow the input of various clinical data. Thanks to the flexible structure of the UMD software, it has been successfully adapted to nine genes either involved in cancer (APC, P53, RB1, MEN1, SUR1, VHL, and WT1) or in genetic diseases (FBN1 and LDLR). Four new LSDBs are under construction (VLCAD, MCAD, KIR6, and COL4A5). Finally, the data can be transferred to core databases.
Collapse
|
35
|
Marquis E, Robert JJ, Benezech C, Junien C, Diatloff-Zito C. Variable features of transient neonatal diabetes mellitus with paternal isodisomy of chromosome 6. Eur J Hum Genet 2000; 8:137-40. [PMID: 10757646 DOI: 10.1038/sj.ejhg.5200401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We describe two patients who suffered transient neonatal diabetes mellitus (TDNM), due to paternal isodisomy of chromosome 6. One patient, now 5 years old, had severe intra-uterine growth retardation, but recovered normal growth parameters. The other patient, currently 12 years old, had a normal birth weight but showed impaired post-natal growth; in addition to TNDM the patient presented with cardiac and thyroid abnormalities. These cases may suggest that the clinical phenotype of TNDM is more variable than previously believed. The contribution of genetic and epigenetic factors needs to be determined to elucidate the phenotype-genotype relationships of this disease.
Collapse
|
36
|
Béroud C, Collod-Béroud G, Boileau C, Soussi T, Junien C. UMD (Universal mutation database): a generic software to build and analyze locus-specific databases. Hum Mutat 1999; 15:86-94. [PMID: 10612827 DOI: 10.1002/(sici)1098-1004(200001)15:1<86::aid-humu16>3.0.co;2-4] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The human genome is thought to contain about 80,000 genes and presently only 3,000 are known to be implicated in genetic diseases. In the near future, the entire sequence of the human genome will be available and the development of new methods for point mutation detection will lead to a huge increase in the identification of genes and their mutations associated with genetic diseases as well as cancers, which is growing in frequency in industrial states. The collection of these mutations will be critical for researchers and clinicians to establish genotype/phenotype correlations. Other fields such as molecular epidemiology will also be developed using these new data. Consequently, the future lies not in simple repositories of locus-specific mutations but in dynamic databases linked to various computerized tools for their analysis and that can be directly queried on-line. To meet this goal, we devised a generic software called UMD (Universal Mutation Database). It was developed as a generic software to create locus-specific databases (LSDBs) with the 4(th) Dimension(R) package from ACI. This software includes an optimized structure to assist and secure data entry and to allow the input of various clinical data. Thanks to the flexible structure of the UMD software, it has been successfully adapted to nine genes either involved in cancer (APC, P53, RB1, MEN1, SUR1, VHL, and WT1) or in genetic diseases (FBN1 and LDLR). Four new LSDBs are under construction (VLCAD, MCAD, KIR6, and COL4A5). Finally, the data can be transferred to core databases.
Collapse
|
37
|
Collod-Béroud G, Lackmy-Port-Lys M, Jondeau G, Mathieu M, Maingourd Y, Coulon M, Guillotel M, Junien C, Boileau C. Demonstration of the recurrence of Marfan-like skeletal and cardiovascular manifestations due to germline mosaicism for an FBN1 mutation. Am J Hum Genet 1999; 65:917-21. [PMID: 10441597 PMCID: PMC1377997 DOI: 10.1086/302545] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
|
38
|
Longuemaux S, Deloménie C, Gallou C, Méjean A, Vincent-Viry M, Bouvier R, Droz D, Krishnamoorthy R, Galteau MM, Junien C, Béroud C, Dupret JM. Candidate genetic modifiers of individual susceptibility to renal cell carcinoma: a study of polymorphic human xenobiotic-metabolizing enzymes. Cancer Res 1999; 59:2903-8. [PMID: 10383153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
The steady increase in sporadic renal cell carcinoma (RCC) observed in industrialized countries supports the notion that certain carcinogens present in the environment (tobacco smoke, drugs, pollutants, and dietary constituents) may affect the occurrence of RCC. Many of the enzymes dealing with such environmental factors are polymorphic and may, therefore, confer variable susceptibility to RCC. This case-control study was designed to test for an association between genetic polymorphism of enzymes involved in xenobiotic metabolism and the risk of sporadic RCC. Genomic DNA was obtained from 173 patients with RCC and 211 controls of Caucasian origin. We used PCR-RFLP to investigate polymorphism for the most common alleles at two cytochrome-P450 mono-oxygenases (CYP1A1 and CYP2D6), one NAD[P]H:quinone oxidoreductase (NQO1), three glutathione S-transferases (GSTM1, GSTT1, and GSTP1), and one N-acetyltransferase (NAT2) loci. The CYP1A1 (m) "variant" genotype, which contains at least one copy of the CYP1A1 variant alleles, was found to be associated with a 2.1-fold [95% confidence interval (CI), 1.1-3.9] increase in the risk of RCC. There was also a higher risk of RCC for subjects with the CYP1A1 (m) variant genotype combined with any of the following genotypes: GSTT1 (+) "active" [odds ratio (OR), 2.3; 95% CI, 1.2-4.5], GSTP1 (m) variant (OR, 2.4; 95% CI, 1.0-5.4), or NAT2 (-) "slow acetylator" (OR, 2.5; 95% CI, 1.1-5.5). A significant association was also found for the GSTM1 (-) "null" and GSTP1 (m) genotypes combined with either NAT2 (-) (OR, 2.6; 95% CI, 1.2-5.8) or CYP1A1 (m) (OR, 3.5; 95% CI, 1.1-11.2). The CYP2D6 (-) "poor metabolizer " and the NQO1 (-) "defective" genotypes were not clearly associated with a higher risk of RCC. Our data demonstrate for the first time a significant association between a group of pharmacogenetic polymorphisms and RCC risk. These positive findings suggest that interindividual variation in the metabolic pathways involved in the functionalization and detoxification of specific xenobiotics is an important susceptibility factor for RCC in Caucasians.
Collapse
|
39
|
Varret M, Rabès JP, Saint-Jore B, Cenarro A, Marinoni JC, Civeira F, Devillers M, Krempf M, Coulon M, Thiart R, Kotze MJ, Schmidt H, Buzzi JC, Kostner GM, Bertolini S, Pocovi M, Rosa A, Farnier M, Martinez M, Junien C, Boileau C. A third major locus for autosomal dominant hypercholesterolemia maps to 1p34.1-p32. Am J Hum Genet 1999; 64:1378-87. [PMID: 10205269 PMCID: PMC1377874 DOI: 10.1086/302370] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Autosomal dominant hypercholesterolemia (ADH), one of the most frequent hereditary disorders, is characterized by an isolated elevation of LDL particles that leads to premature mortality from cardiovascular complications. It is generally assumed that mutations in the LDLR and APOB genes account for ADH. We identified one large French pedigree (HC2) and 12 additional white families with ADH in which we excluded linkage to the LDLR and APOB, implicating a new locus we named "FH3." A LOD score of 3.13 at a recombination fraction of 0 was obtained at markers D1S2892 and D1S2722. We localized the FH3 locus to a 9-cM interval at 1p34.1-p32. We tested four regional markers in another set of 12 ADH families. Positive LOD scores were obtained in three pedigrees, whereas linkage was excluded in the others. Heterogeneity tests indicated linkage to FH3 in approximately 27% of these non-LDLR/non-APOB ADH families and implied a fourth locus. Radiation hybrid mapping located four candidate genes at 1p34.1-p32, outside the critical region, showing no identity with FH3. Our results show that ADH is genetically more heterogeneous than conventionally accepted.
Collapse
|
40
|
de Lonlay-Debeney P, Poggi-Travert F, Fournet JC, Sempoux C, Dionisi Vici C, Brunelle F, Touati G, Rahier J, Junien C, Nihoul-Fékété C, Robert JJ, Saudubray JM. Clinical features of 52 neonates with hyperinsulinism. N Engl J Med 1999; 340:1169-75. [PMID: 10202168 DOI: 10.1056/nejm199904153401505] [Citation(s) in RCA: 216] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Neonatal hyperinsulinemic hypoglycemia is often resistant to medical therapy and is often treated with near-total pancreatectomy. However, the pancreatic lesions may be focal and treatable by partial pancreatic resection. METHODS We studied 52 neonates with hyperinsulinism who were treated surgically. The type and location of the pancreatic lesions were determined by preoperative pancreatic catheterization and intraoperative histologic studies. Partial pancreatectomy was performed in infants with focal lesions, and near-total pancreatectomy was performed in those with diffuse lesions. The postoperative outcome was determined by measurements of plasma glucose and glycosylated hemoglobin and by oral glucose-tolerance tests. RESULTS Thirty neonates had diffuse beta-cell hyperfunction, and 22 had focal adenomatous islet-cell hyperplasia. Among the latter, the lesions were in the head of the pancreas in nine, the isthmus in three, the body in eight, and the tail in two. The clinical manifestations were similar in both groups. The infants with focal lesions had no symptoms of hypoglycemia and had normal preprandial and postprandial plasma glucose and glycosylated hemoglobin values and normal results on oral glucose-tolerance tests after partial pancreatectomy (performed in 19 of 22 neonates). By contrast, after near-total pancreatectomy, 13 of the patients with diffuse lesions had persistent hypoglycemia, type 1 diabetes mellitus developed in 8, and hyperglycemia developed in another 7; overall, only 2 patients with diffuse lesions had normal plasma glucose concentrations in the first year after surgery. CONCLUSIONS Among neonates with hyperinsulinism, about half may have focal islet-cell hyperplasia that can be treated with partial pancreatectomy. These neonates can be identified through pancreatic catheterization and intraoperative histologic studies.
Collapse
|
41
|
Fournet JC, Verkarre V, De Lonlay P, Rahier J, Brunelle F, Robert JJ, Nihoul-Fékété C, Saudubray JM, Junien C. Loss of imprinted genes and paternal SUR1 mutations lead to hyperinsulinism in focal adenomatous hyperplasia. ANNALES D'ENDOCRINOLOGIE 1999; 59:485-91. [PMID: 10189991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Two types of histopathological lesions, a focal adenomatous hyperplasia of islet cells of the pancreas in about 30% of operated sporadic cases, and a diffuse form can be observed in congenital hyperinsulinism, or Persistent Hyperinsulinemic Hypoglycemia of Infancy (PHHI). In sporadic focal forms, specific losses of maternal alleles (LOH) of the imprinted chromosomal region 11p15, restricted to the hyperplastic area of the pancreas, were observed. Similar mechanisms are observed in embryonal tumors and in the Beckwith-Wiedemann syndrome which is also associated with neonatal but transient hyperinsulinism. However this region also contains the sulfonylurea receptor (SUR1) gene and the inward rectifying potassium channel subunit (KIR6.2) gene, involved in recessive familial forms of PHHI, but not known to be imprinted. We now report somatic reduction to hemizygosity or homozygosity of a paternal SUR1 constitutional heterozygous mutation, in five patients with a focal form of PHHI. Thus this somatic event (LOH) which leads both to b cell proliferation and to hyperinsulinism can be considered as the somatic equivalent, restricted to a microscopic focal lesion, of constitutional uniparental disomy associated with unmasking of a heterozygous parental mutation leading to a somatic recessive disorder.
Collapse
|
42
|
Lazarus A, Varin J, Ounnoughene Z, Radvanyi H, Junien C, Coste J, Laforet P, Eymard B, Becane HM, Weber S, Duboc D. Relationships among electrophysiological findings and clinical status, heart function, and extent of DNA mutation in myotonic dystrophy. Circulation 1999; 99:1041-6. [PMID: 10051298 DOI: 10.1161/01.cir.99.8.1041] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Impulse-conduction abnormalities and arrhythmias are common in myotonic dystrophy (MD). This study was performed to determine whether a correlation exists between electrophysiological (EP) testing data and clinical status, heart function, or size of the DNA abnormality (cytosine-thymine-guanine sequence repeat). METHODS AND RESULTS Eighty-three MD patients underwent invasive EP studies prompted primarily by the presence of asymptomatic conduction abnormalities. AV conduction disturbances were common and mainly distal (HV interval, 66.2+/-14 ms). AV conduction observed from the surface ECG was generally concordant with endocardial measurements. However, 11 of 20 patients with normal surface ECGs had abnormal subhisian conduction. Atrial arrhythmias were inducible in 41% of cases and correlated with prolongation of the AH interval (P=0.02) and a shorter atrial refractory period (P=0.04). Induction of ventricular arrhythmias (18%) correlated strongly with age (P=0. 0003). After adjustment for age, the extent of DNA mutation correlated with the Walton score (P=0.0018) but not with conduction abnormalities or induction of arrhythmias. CONCLUSIONS Prolongation of the HV interval is the most common conduction abnormality in MD and can be reliably recognized only by invasive EP testing. It raises the issue of prophylactic pacing to limit the incidence of sudden death in MD. Atrial and ventricular arrhythmias are often inducible, although their predictive value remains to be determined. Young age emerged as the most powerful predictor of inducible ventricular tachyarrhythmias. Conversely, we found no relationship between ECG or EP abnormalities recorded during invasive testing and the DNA mutation size or severity of peripheral muscle involvement.
Collapse
|
43
|
de Lonlay-Debeney P, Fournet JC, Martin D, Poggi F, Dionisi Vicci C, Spada M, Touati G, Rahier J, Brunelle F, Junien C, Robert JJ, Nihoul-Fékété C, Saudubray JM. [Persistent hyperinsulinemic hypoglycemia in the newborn and infants]. Arch Pediatr 1998; 5:1347-52. [PMID: 9885743 DOI: 10.1016/s0929-693x(99)80055-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Persistent hyperinsulinemic hypoglycaemia of infancy (PHHI) is the most frequent cause of hypoglycaemia in infancy. Clinical presentation is heterogeneous, with variable onset of hypoglycaemia and response to diazoxide, and presence of sporadic or familial forms. Underlying histopathological lesions can be focal or diffuse. Focal lesions are characterised by focal hyperplasia of pancreatic islet-like cells, whereas diffuse lesions implicate the whole pancreas. The distinction between the two forms is important because surgical treatment and genetic counselling are radically different. Focal lesions correspond to somatic defects which are totally cured by limited pancreatic resection, whereas diffuse lesions require a subtotal pancreatectomy exposing to high risk of diabetes mellitus. Diffuse lesions are due to functional abnormalities involving several genes and different transmission forms. Recessively inherited PHHI have been attributed to homozygote mutations for the beta-cell sulfonylurea receptor (SUR1) or the inward-rectifying potassium-channel (Kir6.2) genes. Dominantly inherited PHHI can implicate the glucokinase gene, particularly when PHHI is associated with diabetes, the glutamate dehydrogenase gene when hyperammonaemia is associated, or another locus.
Collapse
|
44
|
Rigolet M, Rich T, Gross-Morand MS, Molina-Gomes D, Viegas-Pequignot E, Junien C. cDNA cloning, tissue distribution and chromosomal localization of the human ID4 gene. DNA Res 1998; 5:309-13. [PMID: 9872455 DOI: 10.1093/dnares/5.5.309] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A cDNA e encoding the human Id4 protein has been isolated from an astrocytoma library. The predicted protein product shares 98% identity with the mouse Id4 protein and is markedly different from that already reported. By FISH analysis, the human ID4 gene was more precisely mapped to chromosome 6p22.3-p23. Northern blot analysis showed that ID4 is mainly expressed in thyroid, brain and fetal tissue and in some nervous system tumor cell lines.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Brain/metabolism
- Chromosome Mapping
- Chromosomes, Human, Pair 6
- Cloning, Molecular
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- DNA-Binding Proteins
- Fetus/metabolism
- Gene Expression Regulation, Developmental
- Humans
- In Situ Hybridization, Fluorescence
- Inhibitor of Differentiation Proteins
- Mice
- Molecular Sequence Data
- Nervous System Neoplasms/genetics
- Proteins/chemistry
- Proteins/genetics
- Proteins/metabolism
- Sequence Analysis, DNA
- Thyroid Gland/metabolism
- Transcription Factors
- Tumor Cells, Cultured
Collapse
|
45
|
Verkarre V, Fournet JC, de Lonlay P, Gross-Morand MS, Devillers M, Rahier J, Brunelle F, Robert JJ, Nihoul-Fékété C, Saudubray JM, Junien C. Paternal mutation of the sulfonylurea receptor (SUR1) gene and maternal loss of 11p15 imprinted genes lead to persistent hyperinsulinism in focal adenomatous hyperplasia. J Clin Invest 1998; 102:1286-91. [PMID: 9769320 PMCID: PMC508975 DOI: 10.1172/jci4495] [Citation(s) in RCA: 211] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Congenital hyperinsulinism, or persistent hyperinsulinemic hypoglycemia of infancy (PHHI), is a glucose metabolism disorder characterized by unregulated secretion of insulin and profound hypoglycemia. From a morphological standpoint, there are two types of histopathological lesions, a focal adenomatous hyperplasia of islet cells of the pancreas in approximately 30% of operated sporadic cases, and a diffuse form. In sporadic focal forms, specific losses of maternal alleles (LOH) of the imprinted chromosomal region 11p15, restricted to the hyperplastic area of the pancreas, were observed. Similar mechanisms are observed in embryonal tumors and in the Beckwith-Wiedemann syndrome (BWS), also associated with neonatal but transient hyperinsulinism. However, this region also contains the sulfonylurea receptor (SUR1) gene and the inward rectifying potassium channel subunit (KIR6.2) gene, involved in recessive familial forms of PHHI, but not known to be imprinted. Although the parental bias in loss of maternal alleles did not argue in favor of their direct involvement, the LOH may also unmask a recessive mutation leading to persistent hyperinsulinism. We now report somatic reduction to hemizygosity or homozygosity of a paternal SUR1 constitutional heterozygous mutation in four patients with a focal form of PHHI. Thus, this somatic event which leads both to beta cell proliferation and to hyperinsulinism can be considered as the somatic equivalent, restricted to a microscopic focal lesion, of constitutional uniparental disomy associated with unmasking of a heterozygous parental mutation leading to a somatic recessive disorder.
Collapse
|
46
|
Lia AS, Seznec H, Hofmann-Radvanyi H, Radvanyi F, Duros C, Saquet C, Blanche M, Junien C, Gourdon G. Somatic instability of the CTG repeat in mice transgenic for the myotonic dystrophy region is age dependent but not correlated to the relative intertissue transcription levels and proliferative capacities. Hum Mol Genet 1998; 7:1285-91. [PMID: 9668171 DOI: 10.1093/hmg/7.8.1285] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A (CTG)nexpansion in the 3'-untranslated region (UTR) of the DM protein kinase gene ( DMPK ) is responsible for causing myotonic dystrophy (DM). Major instability, with very large expansions between generations and high levels of somatic mosaicism, is observed in patients. There is a good correlation between repeat size (at least in leucocytes), clinical severity and age of onset. The trinucleotide repeat instability mechanisms involved in DM and other human genetic diseases are unknown. We studied somatic instability by measuring the CTG repeat length at several ages in various tissues of transgenic mice carrying a (CTG)55expansion surrounded by 45 kb of the human DM region, using small-pool PCR. These mice have been shown to reproduce the intergenerational and somatic instability of the 55 CTG repeat suggesting that surrounding sequences and the chromatin environment are involved in instability mechanisms. As observed in some of the tissues of DM patients, there is a tendency for repeat length and somatic mosaicism to increase with the age of the mouse. Furthermore, we observed no correlation between the somatic mutation rate and tissue proliferation capacity. The somatic mutation rates in different tissues were also not correlated to the relative inter-tissue difference in transcriptional levels of the three genes (DMAHP , DMPK and 59) surrounding the repeat.
Collapse
|
47
|
Namouni F, Doz F, Blanquet V, Desjardins L, Validire P, Beroud C, Zucker JM, Quintana E, Junien C. Corrélation phénotype-génotype dans le rétinoblastome : étude d'un sous-groupe de patients ayant présenté des tumeurs secondaires ou une localisation pinéale. Arch Pediatr 1998. [DOI: 10.1016/s0929-693x(98)80193-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
48
|
Verkarre V, Fournet JC, de Lonlay P, Gross-Morand MS, Saudubray JM, Robert JM, Fékété C, Rahier J, Junien C. Identification de mutations du gène sur dans les formes focales sporadiques des hyperinsulinismes persistant du nouveau-né. Arch Pediatr 1998. [DOI: 10.1016/s0929-693x(99)80351-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
49
|
Jeanpierre C, Denamur E, Henry I, Cabanis MO, Luce S, Cécille A, Elion J, Peuchmaur M, Loirat C, Niaudet P, Gubler MC, Junien C. Identification of constitutional WT1 mutations, in patients with isolated diffuse mesangial sclerosis, and analysis of genotype/phenotype correlations by use of a computerized mutation database. Am J Hum Genet 1998; 62:824-33. [PMID: 9529364 PMCID: PMC1377045 DOI: 10.1086/301806] [Citation(s) in RCA: 181] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Constitutional mutations of the WT1 gene, encoding a zinc-finger transcription factor involved in renal and gonadal development, are found in most patients with Denys-Drash syndrome (DDS), or diffuse mesangial sclerosis (DMS) associated with pseudohermaphroditism and/or Wilms tumor (WT). Most mutations in DDS patients lie in exon 8 or exon 9, encoding zinc finger 2 or zinc finger 3, respectively, with a hot spot (R394W) in exon 9. We analyzed a series of 24 patients, 10 with isolated DMS (IDMS), 10 with DDS, and 4 with urogenital abnormalities and/or WT. We report WT1 heterozygous mutations in 16 patients, 4 of whom presented with IDMS. One male and two female IDMS patients with WT1 mutations underwent normal puberty. Two mutations associated with IDMS are different from those described in DDS patients. No WT1 mutations were detected in the six other IDMS patients, suggesting genetic heterogeneity of this disease. We analyzed genotype/phenotype correlations, on the basis of the constitution of a WT1 mutation database of 84 germ-line mutations, to compare the distribution and type of mutations, according to the different symptoms. This demonstrated (1) the association between mutations in exons 8 and 9 and DMS; (2) among patients with DMS, a higher frequency of exon 8 mutations among 46, XY patients with female phenotype than among 46,XY patients with sexual ambiguity or male phenotype; and (3) statistically significant evidence that mutations in exons 8 and 9 preferentially affect amino acids with different functions.
Collapse
|
50
|
Annane D, Fiorelli M, Mazoyer B, Pappata S, Eymard B, Radvanyi H, Junien C, Fardeau M, Merlet P, Gajdos P, Syrota A, Sansom Y, Duboc D. Impaired cerebral glucose metabolism in myotonic dystrophy: a triplet-size dependent phenomenon. Neuromuscul Disord 1998; 8:39-45. [PMID: 9565989 DOI: 10.1016/s0960-8966(97)00144-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Myotonic dystrophy (DM) is caused by an expansion of a CTG triplet repeat sequence in the 3'-noncoding region of a protein kinase gene, yet the mechanism by which the triplet repeat expansion causes disease remains unknown. Impaired glucose penetration into brain tissues has been described in DM patients and is a phenomenon that remains unexplained. The present study shows that altered brain glucose metabolism is triplet repeat dependent. We studied brain glucose metabolism (CMRGlu, mumol/100 g/min) by the use of positron emission tomography and 18F-fluoro-2-deoxy-D-glucose in 11 ambulatory non-obese DM patients and in 11 age and sex matched healthy subjects. All subjects underwent a glucose tolerance test with plasma insulin determinations. The expansion of CTG triplet repeats was analyzed in patients with the probe cDNA25 after EcoRI digestion. As compared to controls, in DM patients, the CMRGlu was significantly decreased (26.26 +/- 5.05 vs. 33.43 +/- 2.18, mumol/100 g/min, P = 0.004), and after oral glucose loading, plasma insulin levels were significantly higher and plasma glucose levels remained unchanged (respectively, F = 11.21, P = 0.004 and F = 0.20, P = 0.66). Subsequently, the glucose/insulin ratio was significantly lower in DM patients (F = 6.25, P = 0.02). The length of the expansion of the CTG repeats correlated negatively with the CMRGlu (r2 = 0.63, P = 0.003) and positively with the area under the curve for insulin changes over time after oral glucose (r2 = 0.49, P = 0.016). We conclude that, in DM patients, the brain metabolism of glucose is impaired in a repeat dependent manner.
Collapse
|