A 28-year-old man and his 27-year-old wife were investigated for infertility of 3 1/2 years' duration. There was azoospermia caused by bilateral aplasia of the vas deferens, and therefore it was planned to aspirate spermatozoa from the epididymis for the purpose of in-vitro fertilisation. As part of the diagnostic workup the man was investigated for those mutations of the cystic fibrosis transmembrane regulator (CFTR) gene which occur with undue frequency in association with aplasia of the vas deferens. Deoxyribonucleic acid (DNA) analysis revealed a typical three base deletion (delta F 508). In the wife, CFTR gene mutations were excluded with 80% probability. The likelihood of cystic fibrosis in this couple's children was accordingly estimated to be about 0.2%--an acceptable risk. Assisted fertilization in patients with bilateral aplasia of the vas deferens should not be undertaken until they have been thoroughly investigated and informed of the risks.

The amount of residual F8 (FVIII:C) determines the clinical severity of hemophilia A. Recently, we showed that the mutation detection rate in severely affected male patients (FVIII:C<1% of normal) is virtually 100% when testing for the common intron 22-/intron 1- inversions and big deletions, followed by genomic sequencing of the F8 gene. Here we report on the spectrum of mutations and their distribution throughout the F8 gene sequence in 135 patients with moderate (n=23) or mild (n=112) hemophilia A. In contrast to the severe form of the disorder, analysis on the genomic level failed to detect the molecular defect in approximately 4% of the moderately and in approximately 12% of the mildly affected patients. A total of 36 of the mutations identified in this study are novel. The vast majority of the detected changes were missense. The newly detected amino acid substitutions were scored for potential distant or local conformational changes and influence on molecular stability for every single F8 domain with available structures, using homology modeling. Two molecular changes in the promoter region of the factor VIII gene (c.-112G>A and -219C>T), affecting the core segment (minimal promoter) were detected in two patients with mild hemophilia A. To our knowledge this is the first report on promoter mutations in the F8 gene.

Hemophilia A is the most frequently occurring X-linked bleeding disorder, affecting one to two out of 10,000 mates worldwide. Various types of mutations in the F8 gene are causative for this condition. It is well known that the most common mutation in severely affected patients is the intron 22 inversion, which accounts for about 45% of cases with F8 residual activity of less than 1%. Therefore, the aim of the present study was to determine the spectrum and distribution of mutations in the F8 gene in a large group of patients with severe hemophilia A who previously tested negative for the common intron 22 inversion. Here we report on a mutation analysis of 86 patients collected under the above-mentioned criterion. The pathogenic molecular defect was identified in all patients, and thus our detection rate was virtually 100%. Thirty-four of the identified mutations are described for the first time. The newly detected amino acid substitutions were scored for potential gross or local conformational changes and influence on molecular stability for every single F8 domain with available structures, using homology modeling.

BACKGROUND:Some of the genetic variants of hemoglobin (Hb) and their chemically modified species are known to affect the measurement of Hb A(1c). The purpose of this study was to characterize Hb species in the blood sample of a 74-year-old German male with an exceptionally low Hb A(1c) value.METHODS:Hemolysates from the propositus and a healthy individual were analyzed by electrophoresis, cation-exchange HPLC, boronate affinity chromatography, and electrospray ionization-mass spectrometry (ESMS). Genomic DNA was amplified by PCR, and the sequencing was performed on an ABI 310 sequencer. Functional properties of Hb were determined by oxygen equilibrium studies and CO recombination kinetics after flash photodissociation. Glycohemoglobin species were synthesized by incubating hemolysates with glucose.RESULTS:A novel, electrophoretically silent beta chain, beta5(A2)Pro-->Ala or Hb Görwihl, was detected by cation-exchange HPLC. It accounted for approximately 44% of the total Hb and had functional properties similar to those of normal Hb A and a mild degree of heat instability. During incubation with glucose, glycation of the beta chains (assessed by ESMS) in the hemolysate of a healthy volunteer was twice as fast as in hemolysate from the propositus.CONCLUSIONS:The substitution beta5(A2)Pro-->Ala seems to affect neither the functional properties nor the heterotropic interactions of Hb, but slows glycation of the N-terminal valine by an unknown mechanism.

Haemophilia A is a X-linked bleeding disorder, caused by deficiency in the activity of coagulation factor VIII due to mutations in the corresponding gene. The most common defect in patients is an inversion of the factor VIII gene that accounts for nearly 45% of individuals with severe hemophilia A. Point mutations and small deletions/insertions are responsible for the majority of cases with moderate to mild clinical course and for half of the severe hemophilia A occurrences. The majority of these mutations are "private", because of the high mutation rate for this particular gene. We report on eleven pathological changes in the factor VIII sequence detected in male patients with haemophilia A or in female obligate carriers. Seven of these mutations are novel [E204N, E265X, M320T, F436C, S535C, N2129M and R2307P] and four have been previously identified [V162M, R527W, R1966X, and R2159C]. Genotype-phenotype correlations and computer prediction analysis on the effect of missense mutations on the secondary structure of the factor VIII protein are performed and the relationships evaluated.

Two hundred and forty-four beta-thalassemia alleles were identified from 135 unrelated occasionally and periodically transfusion dependent beta- and S/beta-thalassemia patients from all regions of Jordan. Allele identification was achieved by PCR amplification of beta-globin genes, dot-blotting the amplified DNA, hybridization with allele specific synthetic probes, and direct sequencing of amplified genomic DNA. A total of 19 different mutations were detected, eight of them constituted about 86% of the Jordanian thalassemic chromosomes. These mutations were IVS1-110 (G>A) (25%), IVS2-1 (G>A) (15%), IVS2-745 (C>G) (14.2%), IVS1-1 (G>A) (10%), IVS1-6 (T>C) (8.3%), codon 37 (G>A) (6.3%), codon 39 (C>T) (4.6%), and codon 5 (-C) (3.8%). The remaining eleven mutations were rare, presented with frequencies ranging between 0.4% and 1.6%. These included two novel mutations and four others detected in Jordan for the first time. The novel mutations were the frame shift (-C) at codon 49 and the substitution (A>C) at position -29 in the TATA box. Four alleles (1.6%) remained unidentified; having no abnormalities in their beta-globin gene sequences and therefore, constituted additional defects causing beta-thalassemia in the Jordanian population. These unknown alleles are expected to be candidates for upstream or downstream mutations affecting the expression of beta-globin gene. The results provided the essential foundation for planning a national preventive program for thalassemia in Jordan and will help improving the medical services for the patients and their families by helping their clinicians and genetic counselors in evaluating their variants and designing their treatment regimens.

Mutations in the large gene of clotting factor VIII (FVIII) are the most common events leading to severe human bleeding disorder. The high proportion of de novo mutations observed in this gene raises the possibility that a significant proportion of such mutations does not derive from a single germ cell but instead should be attributed to a germline or somatic mosaic originating from a mutation during early embryogenesis. The present study explores this hypothesis by using allele-specific PCR to analyze 61 families that included members who had sporadic severe hemophilia A and known FVIII gene defects. The presence of somatic mosaicisms of varying degrees (0.2%-25%) could be shown in 8 (13%) of the 61 families and has been confirmed by a mutation-enrichment procedure. All mosaics were found in families with point mutations (8 [25%] of 32 families). In the subgroup of 8 families with CpG transitions, the percentage with mosaicism increased to 50% (4 of 8 families). In contrast, no mosaics were observed in 13 families with small deletions/insertions or in 16 families with intron 22 inversions. Our data suggest that mosaicism may represent a fairly common event in hemophilia A. As a consequence, risk assessment in genetic counseling should include consideration of the possibility of somatic mosaicism in families with apparently de novo mutations, especially families with the subtype of point mutations.

A new abnormal hemoglobin was detected in a young German anemic patient by cation-exchange high performance liquid chromatography (HPLC). Using a combination of electrospray mass spectrometry, HPLC, direct sequencing, and family screening with polymerase chain reaction/restriction digestion approach, we have characterized this hemoglobin variant as resulting from a Thr --> Ala replacement at beta84(EF8). It could be separated neither by electrophoresis nor by isoelectric focusing. Hb Saale is slightly unstable, exhibiting a moderate tendency to auto-oxidize. Functional properties and the heterotropic interactions are similar to those of Hb A.

A new abnormal hemoglobin was detected in a young German anemic patient by cation-exchange high performance liquid chromatography (HPLC), Using a combination of electrospray mass spectrometry, HPLC, direct sequencing, and family screening with polymerase chain reaction/restriction digestion approach, we have characterized this hemoglobin variant as resulting from a Thr --> Ala replacement at beta 84(EF8). It could be separated neither by electrophoresis nor by isoelectric focusing. Hb Saale is slightly unstable, exhibiting a moderate tendency to auto-oxidize. Functional properties and the heterotropic interactions are similar to those of Hb A.

The beta-thalassemia mutations of 13 unrelated heterozygous Germans who remained unidentified in a previous study of 40 subjects were investigated at the DNA level. Two Mediterranean, one Asian and three novel mutations (CD6 -G, CDs 108 /112-12nt, CDs 130/131 + GCCT) were identified. Altogether, in 30 of the 35 subjects (86%) in which a mutation in the beta-globin gene was identified, the mutation was of Mediterranean origin. The geographical distribution suggests recent migration from the Mediterranean region as cause of the high proportion of frequent Mediterranean beta-thalassemia mutations in the German population. Our results support the notion that the majority of beta-thalassemia genes in the western and central European population are of Mediterranean origin.

A north Thai Y-haplotype database consisting of the loci DYS19, DXYS156-Y, DYS390, DYS391, DYS392, DYS393, and the four subsegments of DYS389 is presented. We observed 44 Y-types in 50 unrelated Thais, and the haplotype diversity was calculated to be 97.36%. No Y-types were shared with a sample of 55 Japanese, but 3 matches were found in a sample of 61 Han Chinese, and there was one Thai-German match in a larger west German sample (n = 179).

Fetuses with homozygous α-thalassaemia develop Hb Bart's hydrops fetalis syndrome, which usually leads either to abortion or fetal/neonatal death. We report diagnosis, intrauterine transfusion therapy, neonatal intensive care management and long-term follow-up of a Vietnamese infant who survived Hb Bart's hydrops fetalis syndrome. During the first 2 years the child had normal development. In addition, the patient exhibited penoscrotal hypospadias. Despite a thorough endocrinological work-up the aetiology of genital ambiguity could not be elucidated. A review of the literature showed an association of homozygous α-thalassaemia and hypospadias in all surviving male children, suggesting a common aetiology for both entities.

Hemophilia A is an X-linked bleeding disease caused by mutations in the coagulation factor VIII gene. The identification and characterization of pathogenic mutations allows the recognition of new mechanisms of functional disturbances of factor VIII. To screen for mutations exons 1-26 of the factor VIII gene have been amplified genomically and analyzed by SSCP followed by direct sequencing of respective exons showing abnormal electrophoretic mobility on SSCP analysis. In the present study we report the detection of four mutations in the factor VIII gene, of which three are novel. The mutational analysis of a patient with severe hemophilia A has revealed that the a ®c transversion at position 3 of the donor-splice-site of intron 23 results in the skipping of exon 23. A novel nonsense mutation Q1778X in exon 16 of factor VIII gene has been identified in a second hemophilia A case. Furthermore two missense mutations have been ascertained: a novel, S183R, causing a mild phenotype of hemophilia A and R282H, previously described in association with severe hemophilia A. Hum Mutat 13:504, 1999. © 1999 Wiley-Liss, Inc.

PAX6 is a candidate gene for familial aniridia. We have carried out a mutational analysis of the PAX6 gene in a three-generation family from Germany, containing 5 individuals affected with ocular abnormalities. In all affected individuals, a heterozygous mutation was detected in the PAX6 gene, exchanging tyrosine 369 by a stop codon. The mutation is located in the 3' moiety of the PST domain, at the C terminus of the PAX6 protein. In the affected family members, the same heterozygous mutation leads to distinct phenotypes of varying severity. Most notably, no aniridia was observed in one of the family members carrying the mutation, although other ocular abnormalities (underdeveloped iris and cataracts) were present. We discuss the possibility that small C terminal truncations of the PAX6 protein might lead to less severe or more divergent phenotypes than trancations at internal positions.

Hemoglobin (Hb) Rambam, or beta69[E13]Gly-->Asp, has been identified in a German woman also suffering from non-insulin-dependent diabetes mellitus and chronic obstructive pulmonary disease. This is the first observation of this Hb variant in a German family thus far. The detailed evaluation of its structure using electrospray mass spectrometry revealed new minor glycohemoglobin components and showed that the attachment of glucose to the beta NH2 terminus occurred at an almost identical rate in both wild-type and mutant beta-chains. However, the introduction of a carboxyl group at beta69 seems to increase the glycation of epsilon-amino groups of lysine residues. The glycemic state in the propositus was well reflected by the total glycohemoglobin concentrations but not by the Hb A1c values, which did not reflect hemoglobin glycation in this patient. This case demonstrates that Hb A1c cannot be used reliably in the management of diabetic patients carrying Hb variants such as Hb Rambam. Functional studies of the whole blood of the heterozygous carrier demonstrated extremely low oxygen affinity, which may have been caused by increased 2,3-diphosphoglycerate related to chronic obstructive pulmonary disease and hyperthyroidism. None of the clinical symptoms could be directly associated to Hb Rambam.

Hemoglobin (Hb) Rambam, or beta 69[E13]Gly-->Asp, has been identified in a German woman also suffering from non-insulin-dependent diabetes mellitus and chronic obstructive pulmonary disease. This is the first observation of this Hb variant in a German family thus far. The detailed evaluation of its structure using electrospray mass spectrometry revealed new minor glycohemoglobin components and showed that the attachment of glucose to the beta NH2 terminus occurred at an almost identical rate in both wild-type and mutant beta-chains. However, the introduction of a carboxyl group at beta 69 seems to Increase the glycation of epsilon-amino groups of lysine residues. The glycemic state in the propositus was well reflected by the total glycohemoglobin concentrations but not by the Hb A(1C) values, which did not reflect hemoglobin glycation in this patient. This case demonstrates that Hb A(1C) cannot be used reliably in the management of diabetic patients carrying Hb variants such as Hb Rambam. Functional studies of the whole blood of the heterozygous carrier demonstrated extremely low oxygen affinity, which may have been caused by increased 2,3-diphosphoglycerate related to chronic obstructive pulmonary disease and hyperthyroidism. None of the clinical symptoms could be directly associated to Hb Rambam.

The X-linked bleeding disorder hemophilia A is caused by mutations in the coagulation factor VIII gene. A high frequency of de novo mutations and the large size of this gene complicate the molecular diagnostic of hemophilia A. Characterization of mutations, however, may help identify amino acids or regions with essential functional or structural properties and thereby clarify the mechanism of pathogenesis. In the present study, we describe the identification of 15 mutations in the factor VIII gene, of which eight are novel. Among the patients with severe hemophilia A, two splice mutations (IVS5-3 and IVS19-2), a 4-bp deletion ((TACA) at codon 1215, and a missense mutation G1850V have been characterized. The missense mutations G479R, R531C, V537D, N2129S and I2190N were found for five patients with a moderate course of hemophilia A disease. A silent mutation resulting in activation of a cryptic acceptor splice site within exon 11 and four other missense mutations Y114C, R1689H, R2150H (2x), M2164V have been identified for six patients with mild hemophilia A.

Human MutationVolume 11, Issue S1 p. S260-S262 Mutation in BriefFree Access Identification of four novel mutations in the factor VIII gene: Three missense mutations (E1875G, G2088S, I2185T) and a 2-bp deletion (1780delTC) Kamiab Tavassoli, Kamiab Tavassoli Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorAntonin Eigel, Antonin Eigel Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorBernd Dworniczak, Bernd Dworniczak Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorElena Valtseva, Elena Valtseva Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorJürgen Horst, Corresponding Author Jürgen Horst Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanyInstitut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Vesaliusweg 12-14, D-48149, Münster, GermanySearch for more papers by this author Kamiab Tavassoli, Kamiab Tavassoli Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorAntonin Eigel, Antonin Eigel Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorBernd Dworniczak, Bernd Dworniczak Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorElena Valtseva, Elena Valtseva Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanySearch for more papers by this authorJürgen Horst, Corresponding Author Jürgen Horst Institut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Münster, GermanyInstitut für Humangenetik der Westfälischen, Wilhelms-Universität Münster, Vesaliusweg 12-14, D-48149, Münster, GermanySearch for more papers by this author First published: 28 April 2011 https://doi.org/10.1002/humu.1380110183Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References Arruda VR, Pieneman WC, Reitsma PH, Deutz-Terlouw PP, Annichino-Bizzacchi JM, Briet E, Costa FF (1995) Blood 86: 3015– 3020. Elder B, Lakich D, Gitschier J (1993) Genomics 16: 374– 379. Foster PA, Fulcher CA, Houghten RA, Zimmerman TS (1990) Blood 75: 1999– 2004. Gitschier J, Wood WI, Goralka TM, Wion KL, Chen EY, Eaton DE, Vehar GA, Capon DJ, Lawn RM (1984) Nature 312: 326– 330. Gyllensten UB, Erlich HA (1988) Proc Natl Acad Sci USA 85: 7652– 7656. Higuchi M, Kazazian HH, Kasch L, Warren TC, McGinniss MJ, Phillips JA, Kasper C, Janco R, Antonarakis SE (1991) Proc Natl Acad Sci USA 88: 7405– 7409. Kane WH, Davie EW (1986) Proc Natl Acad Sci USA 83: 6800– 6804. Koschinsky ML, Funk WD, van Oost BA, MacGillivray RTA (1986) Proc Natl Acad Sci USA 83: 5086– 5090. Lakich D, Kazazian HH, Antonarakis SE, Gitschier J (1993) Nature Genet 5: 236– 241. Naylor JA, Green PM, Montandon JA, Rizza CR, Giannelli F (1991) Lancet 337: 635– 639. Naylor JA, Brinke A, Hassoc S, Green PM, Giannelli F (1993) Hum Mol Genet 2: 1773– 1778. Poole S, Firtel RA, Lamar E, Rowekamp W (1981) J Molec Biol 153: 273. Sanger F, Nicklen S, Coulson AR (1977) Proc Natl Acad Sci USA 74: 5463– 5467. Schwaab R, Oldenburg J, Schwaab U, Johnson DJD, Schmidt W, Olek K, Brackman HH, Tuddenham EGD (1995) Br J Haematol 91: 458– 464. Wacey AI, Kemball-Cook G, Kazazian HH, Antonarakis SE, Schwaab R, Lindley P, Tuddenham EGD (1996) Nucleic Acids Res 24: 100– 102. Citing Literature Volume11, IssueS1Supplement: Human Mutation1998Pages S260-S262 ReferencesRelatedInformation