Geographic distribution of CDA-II: did a founder effect operate in Southern Italy?

BACKGROUND AND OBJECTIVE

Congenital dyserythropoietic anemia type II (CDA-II) is an autosomal recessive condition, whose manifestations range from mild to moderate. Its exact prevalence is unknown. Based on a recently established International Registry of CDA-II (64 unrelated kindreds), a high frequency of CDA II families living in South Italy became evident.

DESIGN AND METHODS

The aim of this study was to define the haplotypes of the CDA II kindreds living in Southern Italy based on markers D20S884, D20S863, RPN, D20S841 and D20S908. These markers map to 20q11.2, within the interval of the CDAN2 gene that is responsible for CDA II. Next, we looked at these markers in kindreds from other regions of Italy and from other countries, with special attention to families having ancestors in Southern Italy.

RESULTS

Evaluation of the geographic distribution of the ancestry of Italian CDA-II patients clearly demonstrated the unusually high incidence of this condition in Southern Italy. Our statistical calculations and linkage disequilibrium data also clearly demonstrate a strong association of the markers of chromosome 20 with the disease locus in our sample. Almost all the regions defined by the markers here used is in disequilibrium with the disease. Combining the data from the Italian sample together with those obtained from the non-Italian ones, we can restrict the area of highest disequilibrium to that defined by markers D20S863-D20S908.

INTERPRETATION AND CONCLUSIONS

Despite the presence of this linkage disequilibrium the search for a common haplotype failed. This could suggest that the mutation was very old or that it occurred more than once on different genetic backgrounds.

[Mixed carcinoid-adenocarcinoma tumor of the appendix: a case report and diagnostic and therapeutic considerations]

The layout of the work has stayed motivated from the recent observation of mixed carcinoid, located to the appendix and wide to the peritoneal cable, joint to our observation in an elderly patient with aspecific demonstration clinical-symptomatologic. The study of the endocrine tumors is in continuous evolution also if, to the actual state, there is a better comprehension of this neoplasm, variegated and complex and, under some appearances, still not known well. Jejunoileal carcinoid tumors differ, under many appearances, from those occurring in other sites of the gut. They have relatively high rate of transmural invasion and aggressive clinical behavior, contrasted by a scarce objectivity; the demonstration of symptoms generally implicates the presence of an illness in advanced stage. Also pharmacological therapy made important progress, with the possibility of administer composed able to interfere with the development and the neoplastic growth.

Identification of LMX1B gene point mutations in italian patients affected with Nail-Patella syndrome

Nail-Patella syndrome, or osteo-onychodysplasia, is an autosomal dominant disorder characterized by nail dysplasia, absent or hypoplastic patellae, iliac horns and nephropathy. Previous studies have demonstrated linkage of the Nail-Patella locus with polymorphic markers on human chromosome 9q34. Recently, point mutations in the LMX1B gene have been identified in Nail-Patella patients and in families with recurrence of Nail-Patella syndrome and open-angle glaucoma. We describe here the identification of additional point mutations in the LMX1B gene in a set of Italian patients affected with Nail-Patella syndrome: two deletions of 1 and 2 bp causing a frameshift in two sporadic patients and nonsense mutations in two familial and one sporadic cases have been identified. All the mutations affect the homeodomain of the LMX1B protein and could cause the Nail-Patella syndrome through a loss of function as well as a dominant negative effect. Haplotype analysis in the two familial cases carrying the same stop codon mutation suggests the presence of a founder effect. Finally, analysis of cDNA clones obtained from human fetal kidney has revealed the existence of two different transcripts of LMX1B gene likely due to an alternative splicing.

Familial pseudohyperkalemia maps to the same locus as dehydrated hereditary stomatocytosis (hereditary xerocytosis)

Familial pseudohyperkalemia is a "leaky red blood cell" condition in which the cells show a temperature-dependent loss of potassium (K) from red blood cells when stored at room temperature, manifesting as apparent hyperkalemia. The red blood cells show a reduced lifespan in vivo but there is no frank hemolysis. Studies of cation content and transport show a marginal increase in permeability at 37 degrees C and a degree of cellular dehydration, qualitatively similar to the changes seen in dehydrated hereditary stomatocytosis (hereditary xerocytosis). Physiological studies have shown that the passive leak to K has an abnormal temperature dependence, such that the leak is less sensitive to temperature than that in normal cells. We performed genetic mapping on the original family and found that the condition in this kindred maps to the same locus (16q23-ter) that we have previously identified for an Irish family with dehydrated hereditary stomatocytosis, which does not show the same temperature effects.

Juvenile hemochromatosis locus maps to chromosome 1q

Juvenile hemochromatosis (JH) is an autosomal recessive disorder that leads to severe iron loading in the 2d to 3d decade of life. Affected members in families with JH do not show linkage to chromosome 6p and do not have mutations in the HFE gene that lead to the common hereditary hemochromatosis. In this study we performed a genomewide search to map the JH locus in nine families: six consanguineous and three with multiple affected patients. This strategy allowed us to identify the JH locus on the long arm of chromosome 1. A maximum LOD score of 5.75 at a recombination fraction of 0 was detected with marker D1S498, and a LOD score of 5. 16 at a recombination fraction of 0 was detected for marker D1S2344. Homozygosity mapping in consanguineous families defined the limits of the candidate region in an approximately 4-cM interval between markers D1S442 and D1S2347. Analysis of genes mapped in this interval excluded obvious candidates. The JH locus does not correspond to the chromosomal localization of any known gene involved in iron metabolism. These findings provide a means to recognize, at an early age, patients in affected families. They also provide a starting point for the identification of the affected gene by positional cloning.

Cloning of a new gene (FB19) within HLA class I region

A novel gene (named FB19) has been identified within the HLA class I region at human chromosome 6p21.3. A 4.5-kb cDNA containing a 2820-bp open reading frame for a predicted protein of 940 aa was identified. No homology with known gene was detected at the DNA level, while the predicted protein is characterized by a glycine-rich region followed by a domain of 35 residues that shows high homology with the CAT56 gene, another gene of MHC class I. A 4. 5-kb transcript was detected in several tissues and cell lines, clearly indicating a wide distribution of expression. Once its function is defined, it could be possible to investigate the relationship between the FB19 gene and the several diseases already mapped within the HLA class I region.

GABA (gamma-amino-butyric acid) neurotransmission: identification and fine mapping of the human GABAB receptor gene

GABA (gamma-amino-butyric acid) receptors are a family of proteins involved in the GABAergic neurotransmission of the mammalian central nervous system (CNS). They have physiological importance and clinical relevance in several diseases. We report the identification, cloning, and fine mapping of the human cDNA for GABAB receptor. A 4.2-Kb cDNA containing an open reading frame for a predicted protein of 960 aa was isolated from a fetal brain cDNA library. It had a strong identity (91.5%) with the rat GABAB receptor (rGB1A) nucleotide sequence, that corresponded to 98.6% identity at the amino acid level. Expression of the GABAB at the transcription level was detected by Northern analysis in all brain areas examined. The GABAB receptor has been mapped to human chromosome 6p21.3 within the HLA class I region close to the HLA-F gene. Susceptibility loci for multiple sclerosis, epilepsy, and schizophrenia have been suggested to map in this region.

[Diagnosis of hereditary hemochromatosis with molecular analysis of DNA in patients with anti-HCV positive liver cirrhosis. Clinical case]

A case of hereditary hemochromatosis in a patient affected by anti-HCV positive liver cirrhosis is described. The difficulties for an exact diagnosis are underlined. Really, it can be particularly difficult to make a differential diagnosis between hereditary hemochromatosis and secondary hemochromatosis, if liver cirrhosis has already been found. Practically, at this stage of disease, the histological and clinical aspects of these two forms become completely interchangeable. Moreover, diagnostic difficulties increase when, at the same time, the patient presents more causes of potential liver damage. In this case report, the DNA-analysis, obtained by polymerase chain reaction amplification and enzymatic digestion, allows to make the diagnosis of hereditary hemochromatosis, because it showed the presence of two genetic mutations, considered responsible for the disease. Both the hereditary hemochromatosis and the HCV infection, had greatly contributed to the development of liver cirrhosis. In the future, DNA-analysis by amplification with polymerase chain reaction, can assume relevant importance for the screening of affected patients' first grade parents too. It could permit an early diagnosis of hereditary hemochromatosis and then to start a timelier and more efficacious therapy, to prevent an irreversible histological damage.

Genomewide search for dehydrated hereditary stomatocytosis (hereditary xerocytosis): mapping of locus to chromosome 16 (16q23-qter)

Dehydrated hereditary stomatocytosis, also known as "hereditary xerocytosis," is caused by a red blood cell-membrane defect characterized by stomatocytic morphology, increased mean corpuscular hemoglobin concentration, decreased osmotic fragility, increased permeability to the univalent cations Na+ and K+, and an increased proportion of phosphatidylcholine in the membrane. The clinical presentation is heterogeneous, ranging from mild to moderate hemolytic anemia associated with scleral icterus, splenomegaly, and choletithiasis. Iron overload may develop later in life. The disease is transmitted as an autosomal dominant trait. We recruited a large three-generation Irish family affected with DHS and comprising 23 members, of whom 14 were affected and 9 were healthy. Two additional, small families also were included in the study. The DNA samples from the family members were used in a genomewide search to identify, by linkage analysis, the DHS locus. After the exclusion of a portion of the human genome, we obtained conclusive evidence for linkage of DHS to microsatellite markers on the long arm of chromosome 16 (16q23-q24). A maximum two-point LOD score of 6.62 at recombination fraction .00 was obtained with marker D16S520. There are no recombination events defining the telomeric limit of the region, which therefore is quite large. No candidate genes map to this area.

Linkage analysis in two large Italian pedigrees affected with nail patella syndrome

Nail patella syndrome (NPS) or osteo-onychodysplasia, is an autosomal dominant disorder characterised by nail dysplasia, absent or hypoplastic patellae, iliac horns and nephropathy. Previous studies have demonstrated linkage of the nail patella locus to the ABO and adenylate kinase loci on human chromosome 9q34. Recently, informative recombination events placed the NPS locus within a 1-2 cM interval within D9S60 and the AK1 gene. We describe here linkage analysis performed in two large Italian pedigrees with 10 and 11 members affected, respectively. A set of highly informative markers have been analysed and the allele segregation in the two families confirmed the linkage to chromosome 9. The presence of three recombination events allows definition of the critical region with a centrometric boundary between markers D9S1881 and D9S1840 and a telomeric boundary between markers D9S315 and D9S290.

Generation of a transcription map of a 1 Mbase region containing the HFE gene (6p22)

A transcription map was generated of a 1 Mb interval including the HFE gene on 6p22. Thirty-seven unique cDNA fragments were characterised following their retrieval from hybridisation of immobilised YACs to primary pools of cDNAs prepared from RNA of foetal brain, human liver, foetal human liver, placenta, and CaCo2 cell line. All cDNA fragments were positioned on the physical map on the basis of presence in aligned and overlapping YACs and cosmid clones of the region. The isolated cDNAs together with established or published sequence tagged sites (STSs) and markers provided sufficient landmark density to cover approximately 90% of the 1 Mb interval with cosmid clones. The precise localisation of two known genes (NPT1 and RING finger protein) was established. A minimum of 14 additional transcription units has also been integrated. Twenty-eight cDNA fragments showed no similarity with known sequences, but 20 of these detected discrete mRNAs upon northern analysis. Their characterisation is still under investigation. Eleven new polymorphisms were also identified and localised, and the HFE genomic structure was better defined. This integrated transcription map considerably extends a recently published map of the HFE region. It will be useful for the identification of genetic defects mapping to this region and for providing template resources for genomic sequencing.

Juvenile and adult hemochromatosis are distinct genetic disorders

Juvenile Hemochromatosis (JH) is a rare genetic disorder that causes iron overload. JH clinical features are similar to those of hemochromatosis (HFE), but the clinical course is more severe and is characterized by an earlier onset and by a prevalence of cardiac symptoms and endocrine dysfunctions. Here we describe seven Italian patients belonging to five unrelated families with clinical features typical of JH. In four out of five families the parents were consanguineous. Analysis of HFE gene mutations in all the cases and nucleotide sequence of the gene in one case excluded this gene as responsible for JH. Segregation analysis of 6p markers closely associated with HFE in families with consanguineous parents clearly showed that JH is unlinked to 6p and thus genetically distinct from HFE.

A YAC contig spanning the blepharophimosis-ptosis-epicanthus inversus syndrome and propionic acidemia loci

Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is an autosomal dominant condition consisting of congenital dysplasia of the eyelids with a reduced horizontal diameter of the palpebral fissures, droopy eyelids and epicanthus inversus. Two clinical entities have been described: type I and type II. The former is distinguished by female infertility, whereas the latter presents without other symptoms. Both type I and type II were recently mapped on the long arm of chromosome 3 (3q22-q23), suggesting a common gene may be affected. The centromeric and the telomeric limits of this region are well defined between loci D3S1316 and D3S1615, which reside approximately 5 cM apart. Here, we present the construction of a YAC contig spanning the entire BPES locus using 17 polymorphic markers, 2 STS and 28 ESTs. This region of approximately 5 Mb was covered by 31 YACs, and was supported by detailed FISH analysis. In addition, we have precisely mapped the propionyl-CoA carboxylase beta polypeptide (PCCB), the gene mutated in propionic acidemia, within this contig. Apart from providing a framework for the identification of the BPES gene, this contig will also be useful for the future identification of defects and genes mapped to this region, and for developing template resources for genomic sequencing.

Mutation analysis of the HLA-H gene in Italian hemochromatosis patients

Hemochromatosis (HH) is an inborn error of iron metabolism, frequent among Caucasians, characterized by progressive iron loading that, if untreated, causes high morbidity and death. HLA-H, a putative HH gene, has recently been isolated. The large majority of patients so far studied are homozygous for a single mutation, which results in a cysteine-to-tyrosine substitution at amino acid 282 of the protein. A second, less frequent, variant, His63Asp, has an undefined role in the pathogenesis of the disease. Here we report that the Cys282Tyr change accounts for 69% of HH chromosomes in a series of 75 unrelated Italian patients who fulfilled well-defined criteria for HH diagnosis. Sixty-four percent of patients were Cys282Tyr homozygous, 10% were heterozygous, and 21% carried the normal allele. The same mutation was rare in normal controls. The His63Asp variant was less frequent but had a similar frequency among affected and normal chromosomes. Subjects without two copies of the Cys282Tyr change were both isolated patients and individuals from families with a 6p-linked disease. Mutation analysis of the HLA-H gene, carried out by RNA-SSCP in the latter patients, did not reveal any significant nucleotide abnormality in coding sequences and intron-exon boundaries. The absence of mutations in HLA-H gene was confirmed in three cases by direct sequencing. Major deletions or rearrangements of the gene were excluded by Southern blotting. The existence of patients with clinical and histological features of HH, but without mutations in HLA-H gene, suggests that in Italy the disease is more heterogeneous than reported in northern Europe.

A recombination event close to HFE gene in hereditary hemochromatosis

A candidate gene for Hereditary Hemochromatosis (HFE) has been recently cloned from a region 4 cM telomeric to HLA-A on the short arm of chromosome 6. This gene, defined HFE, is mutated in a high proportion of HFE patients. Positional cloning of HFE has been difficult, because of the extended region of linkage disequilibrium observed around the gene and of the rarity of recombination events in this DNA area. Here we describe a crossover in an Italian HFE patient which occurred close to the HFE gene in a restricted interval between D6S2221 and D6S2240-D6S2238 markers. The molecular analysis of this event and the segregation of the HFE mutations in the family are consistent with the position of the HFE gene telomeric to D6S2221.

[Ureteral jet in patients with benign prostatic hypertrophy: prognostic evaluation during single and combined therapy]

By color-Doppler ultrasound it's possible to visualize urine flow jet from ureter into the bladder. Aim of the study was to evaluate of ureteral jet in patients with benign prostatic hyperplasia before, during and after with one or two drugs medical therapy. Thirteen patients, aged 51-63 years, were studied; they were not affected by metabolic, hepatic, renal diseases and by prostate inflammation. Eco color Doppler p.w. (Toshiba SSA 270A) with a convex probe of 3.5 MHz was used. A transabdominal ultrasound study was performed, prostate volume measured and ureteral jet visualized before and along treatment (at six months interval) with Finasteride and at the end of treatment. Successively, in four patients, with relapse of prostatic synptomatology, a transabdominal ultrasound study was performed, before and along a treatment with Finasteride, 5 mg/die (Finastid, Neopharmed) and Terazosin hydrochloride, 5 mg/die (Teraprost, Malesci), and at the end of treatment.

Construction of a YAC contig covering human chromosome 6p22

A contig covering human chromosome 6p22 that consists of 134 YAC clones aligned based on the presence/absence of 52 DNA markers is presented. This contig overlaps with the 6p23 contig at its telomeric end and with the 6p21.3 contig at its centromeric end. The order of loci within the contig resolves the relative positions of several genetically mapped markers. Among the additional markers used here, there are eight novel PCR assays. The 12 known genes and anonymous ESTs located within the contig establish a first step toward a transcriptional map of this region. The instability of YAC clones observed during this work is also discussed.

Hereditary hemochromatosis: generation of a transcription map within a refined and extended map of the HLA class I region

Hereditary hemochromatosis, a common severe inherited disease, maps to the short arm of chromosome 6 close to the HLA-A locus. Recently, linkage data on Italian and French populations confirmed this location, while a similar analysis on Australian and British populations located the gene closer to D6S105, a marker residing telomeric of HLA-A. To increase our knowledge on the region of highest linkage disequilibrium in our population and possibly to identify the disease gene, a 1.2-Mb detailed physical and transcription map was generated, spanning the HLA class I region. Thirty-eight unique cDNA fragments, retrieved following the hybridization of immobilized YACs to primary pools of cDNAs prepared from RNA of fetal brain, adult brain, liver, placenta, and the CaCo2 cell line, were characterized. All cDNA fragments were positioned in a refined and extended map of the human major histocompatibility complex spanning from HLA-E to approximately 500 kb telomeric of HLA-F. The localization of known genes was refined, and a new gene from the RNA helicase superfamily was identified. Overall, 14 transcription units in addition to the HLA genes have been detected and integrated in the map. Thirteen cDNA fragments show no similarity with known sequences and could be candidates for the disease. Their characterization and assessment for involvement in hemochromatosis are still under investigation. Seven new polymorphisms, some tightly linked to the disease, were also identified and localized.

Are patients with acute leukaemia, alive and well 2 years post bone marrow transplantation cured? A European survey. Acute Leukaemia Working Party of the European Group for Bone Marrow Transplantation (EBMT)

We investigated the occurrence of late events (beyond 2 years) in patients with acute leukaemia who received an allogeneic (BMT) (n = 1059), or an autologous bone marrow transplantation (ABMT) (n = 656) in Europe during the period from January 1979 to December 1990. Patients with no recurrence of leukaemia at 2 years had overall 82% chance of being alive in complete remission at 9 years following transplantation regardless of the nature of the leukaemia, the status at transplant, and the type of transplant. The incidence of late relapses continuously decreased with time. The latest relapses in acute myelogenous leukaemia (AML) were observed following BMT at 6.6 years in a patient transplanted in first remission (CR1) and at 3.7 years in a patient transplanted in second remission (CR2), and following ABMT at 6 years and 5.1 years respectively. The latest relapses in acute lymphoblastic leukaemia (ALL) were observed following BMT at 4 years in a patient transplanted in first remission (CR1) and at 6.8 years in a patient transplanted in second remission (CR2), and following ABMT at 5.3 years and 4.5 years respectively. Several factors predictive for late relapse or death were identified. Patients allografted experienced a lower frequency of late relapse than patients autografted. Of the numerous other prognostic factors studied, female sex in AML, the use of total body irradiation (TBI) in ALL and status in CR1, rather than CR2-3, for both ALL and AML allografted were correlated with a lower relapse incidence. The use of TBI in ALL was also associated with a better LFS and survival. The absence of acute graft-versus-host disease (GVHD) in allografted AML correlated with better LFS and better survival, but had no influence on the relapse incidence. This study indicates that patients alive and well at 2 years post transplant have a very high probability of being cured, but the possibility of late relapse still remains.

Treatment of severe aplastic anemia with sequential immunosuppression

Forty-two patients with severe aplastic anemia (SAA) were treated with immunosuppressive therapy (IS) consisting of one or more courses of the following regimens: a) high dose bolus 6 methylprednisolone (BMPr); b) horse antilymphocytic globulin (HALG); c) rabbit ALG (RALG); d) ALG followed by the infusion of haploidentical marrow (ALG +/- BM); e) BMPr in combination with HALG; f) ALG in combination with androgens. All patients received one initial course of IS: 16 (38%) showed hematologic reconstitution and required no further transfusions, of 26 refractory patients 4 died, and 22 received a second course of IS 60 days after the first course. Of these 22, 6 (27%) responded, and of the 16 refractory patients, 9 died, and 7 received a third course of IS 60 days after the second course. Two of these responded (28%), 3 died and 2 are alive but pancytopenic. The overall response rate is 24/42 patients (57%): all of these patients are transfusion independent 6-60 months post-treatment, and 17 are off maintenance therapy with low dose steroids. The actuarial 5 year survival is currently 60%; 13/26 surviving patients have been followed for more than 3 years. The present study confirms that over 50% of patients with SAA can recover from their aplasia following IS treatment, and this is of relevance for patients who can not be offered a bone marrow transplant.

Lymphoid antigens on blast cells in the agranular metamorphosis of chronic myelogenous leukaemia

Undifferentiated blasts from a Ph'-positive chronic myelogenous leukaemia (CML) in terminal metamorphosis were reacted in an indirect immunofluorescence test with antilymphocytic globulins (AHLGs), raised against cultured lymphoblasts, thoracic duct and peripheral blood lymphocytes from healthy donors. After proper myeloid and/or monocytic absorptions the AHLGs interacted strongly with the undifferentiated blasts of CML, while this was not true for parallel controls with non-lymphoid leukaemias, both acute and chronic. The intensity of fluorescence, as determined by the use of a microfluorimeter, on these agranular blasts was comparable to the positivity of lymphoid cells from acute and chonic lymphatic leukaemias. These findings lend further support to the conception of a lymphoblast-like variety of terminal blastic crisis in chronic myelogenous leukaemia.

The formation of deoxycholic acid in patients with type II and IV hyperlipoproteinaemia

The formation of deoxycholic acid (D) was studied in 8 patients with Type II hyperlipoproteinaemia and in 6 with Type IV hyperlipoproteinaemia, using orally administered [2.4--3H]cholic acid and [24--14C]deoxycholic acid. The diet was standardized and of natural type. The mean values for fractional turnover, pool size and D synthesis in the patients with Type II pattern were 0.23 days-1, 331 mg and 75 mg/day, respectively; in Type IV they were 0.39 days-1, 587 mg and 191 mg/day. Compared with a group of healthy subjects, the pool size and formation of D were normal in Type IV, but significantly reduced in Type II. The mean conversion of cholic acid into the circulating pool of D was calculated to be 37% in Type II, and 38% in Type IV patients. Both these values are within normal limits.