Elisena Morizio

A quarter of men with idiopathic oligo-azoospermia display chromosomal abnormalities and microdeletions of different types in interval 6 of Yq11.

Cytogenetic investigations and molecular analysis of the Y chromosome by the polymerase chain reaction amplification of sequence-tagged sites (STS-PCR) technique were performed in 126 patients affected by idiopathic oligo-azoospermia following accurate selection of cases. Seventeen patients evidenced an abnormal karyotype. Fourteen patients with a normal karyotype had microdeletions of the Y chromosome within interval 6. In azo-ospermic patients microdeletions were scattered along different subintervals, while in oligozoospermic patients they were clustered in subinterval 6E. The size of the deletion was not apparently related to the severity of the disease. These results suggest that cytogenetic analysis and the STS-PCR technique can detect a genetic cause of infertility in about one-quarter of patients with idiopathic oligo-azoospermia.

C677T mutation in the 5,10-MTHFR gene and risk of Down syndrome in Italy.

The C677T polymorphism of the MTHFR gene has been associated to maternal risk of Down syndrome, due to the detection of an higher prevalence of the T allele among mothers of children with trisomy 21, compared to control mothers. In order to confirm this association, we studied the presence of the C677T in 64 mothers of Down syndrome children and 112 controls from central Italy. An higher incidence of the mutant T allele in controls (48.2%) than in Down syndrome children mothers (44%) was detected. These results do not support the presence of an increased risk of Down syndrome in mothers carriers of the T allele in the Italian population.

Isolation of osteogenic progenitors from human amniotic fluid using a single step culture protocol

BackgroundStem cells isolated from amniotic fluid are known to be able to differentiate into different cells types, being thus considered as a potential tool for cellular therapy of different human diseases. In the present study, we report a novel single step protocol for the osteoblastic differentiation of human amniotic fluid cells.ResultsThe described protocol is able to provide osteoblastic cells producing nodules of calcium mineralization within 18 days from withdrawal of amniotic fluid samples. These cells display a complete expression of osteogenic markers (COL1, ONC, OPN, OCN, OPG, BSP, Runx2) within 30 days from withdrawal. In order to test the ability of these cells to proliferate on surfaces commonly used in oral osteointegrated implantology, we carried out cultures onto different test disks, namely smooth copper, machined titanium and Sandblasted and Acid Etching titanium (SLA titanium). Electron microscopy analysis evidenced the best cell growth on this latter surface.ConclusionThe described protocol provides an efficient and time-saving tool for the production of osteogenic cells from amniotic fluid that in the future could be used in oral osteointegrated implantology.

Complex translocations of the Ph chromosome and Ph negative CML arise from similar mechanisms, as evidenced by FISH analysis

The authors report on 13 patients with chronic myeloid leukemia (CML) studied by serial karyotyping and fluorescence in situ hybridization (FISH) of their bone marrow cells. Ten patients had complex translocations of the Ph chromosome while the remaining three were Ph negative. FISH analysis revealed in all 13 patients the translocation of the ABL protooncogene into chromosome 22 at band q11. Moreover, in all complex translocations but one, FISH with a chromosome 22 painting probe demonstrated on one chromosome 9 at band q34 the presence of material from chromosome 22, in addition to signals on the third chromosome involved in complex changes. Therefore, in this study complex translocations appeared as secondary changes resulting from two consecutive translocations with a total of at least four breaks. The first translocation gave rise to the standard t(9;22)(q34;q11). The second one included a break distal to the original breakpoint at band 9q34 and another one on a third chromosome. Furthermore FISH using S1 and S15 probes, mapped at band 22q11.2 or 22q12, gave evidence that in complex translocations the secondary breakpoint on der(9) was in the translocated segment 22q11-qter between bands q11 and q12. FISH analysis also disclosed the presence of material from chromosome 22 on one chromosome 9 in the three patients with Ph negative CML, demonstrating that in these cases a retranslocation between chromosomes 9q+ and 22q- had occurred. Consequently, the four-break mechanism could also be invoked for the three Ph negative CML patients.

p53 loss and point mutations are associated with suppression of apoptosis and progression of CML into myeloid blastic crisis

A longitudinal investigation using fluorescence in situ hybridization (FISH) analysis, PCR-SSCP, and in situ detection of apoptosis by the terminal deoxynucleotidyl Transferase (TdT) method was carried out on 13 chronic myelogenous leukemia (CML) patients to study the p53 gene behavior and the apoptotic process during the course of the disease. At diagnosis, FISH showed no loss of the p53 gene on interphase nuclei, and no point mutation was detected by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) and sequencing. During the disease course, FISH analysis showed a significative loss of allele (LOA) rate for the p53 gene in eight patients that in seven cases was associated with a suppression of apoptotic process and the progressive expansion of the p53+/p53- clone. DNA sequencing showed in two of these eight patients a point mutation on the other allele, consisting in the formation of a stop codon in one case, and in a frameshift mutation in the other. Six patients had a myeloid blastic crisis (BC), five a lymphoid BC, and the other two an erythroid and an undifferentiated BC, respectively. All patients with myeloid BC and the one with undifferentiated BC disclosed a progressive expansion of the clone with p53 loss that was associated with a significant reduction in apoptosis. On the contrary in the 5 patients with lymphoid BC no significant p53 LOA rate was observed during the course of the disease. In these patients apoptotic process also persisted in the acute phase although in a lower rate as compared to CP.

A new case of Yq microdeletion transmitted from a normal father to two infertile sons

During the last few years, microdeletions of the long arm of the Y chromosome, involving loci AZFa, AZFb, and AZFc, have been identified as a major cause of infertility, leading to the disruption of genes involved in spermatogenesis. These microdeletions are usually de novo mutations, but in six cases transmission from fertile fathers to infertile sons has been reported. In four cases, the transmission occurred to a single son, and in one of these a widening of the deletion was shown.1–4 In the remaining two cases, the microdeletion was transmitted to multiple sons, resulting in different defects of spermatogenesis.5,6 Here, we describe a third family with a Yq microdeletion transmitted by a father to his two infertile sons.

SHOX mutations detected by FISH and direct sequencing in patients with short stature

Height is the result of interactions of several factors including those of genetic origin. About 3% of people have short stature and in most of them the cause is unknown.1 Recently, the SHOX gene (short stature homeobox containing gene), mapped on the pseudoautosomal region (PAR1) of the X and Y chromosomes, has been specifically associated with the short stature of patients with Turner syndrome or with Leri-Weill dyschondrosteosis (LWD).2–7 Few data have been reported on the relationship between SHOX mutations and idiopathic short stature. Rao et al 2 reported one change among 91 patients with idiopathic short stature, and Binder et al 8 found a mutation in one out of 68 patients. The largest study was recently published by Rappold et al ,9 who found a frequency of 2.4% of SHOX mutations using fluorescence in situ hybridisation (FISH) on 150 patients and single strand conformational polymorphism analysis (SSCP) on 750 patients. We report a study carried out on 56 patients with short stature of unknown origin detecting SHOX mutations in seven (12.5%) by using FISH and direct sequencing analyses. ### Patients Fifty-six patients, 33 females and 23 males, with a mean age of 12.2 years (range 5-18 years) entered this study. All patients were unrelated, coming from different regions of central and southern Italy. In order to exclude patients with dyschondrosteosis or other diseases associated with short stature, we used the following criteria: (1) height at or below the 3rd centile; (2) absence of obvious skeletal abnormalities on physical examination; (3) absence of other diseases on physical examination and routine analyses; (4) normal bone age; (5) normal hGH values using a polyclonal in house RIA (lower detection limit 0.1 ng/μl, mean intra-assay coefficient of variation 6.9%, and mean interassay coefficient 9.5%); and (6) normal karyotype in 16 metaphases …

Identification and characterization of different SHOX gene deletions in patients with Leri–Weill dyschondrosteosys by MLPA assay

AbstractDeletions of the SHOX gene (Xp22-Yp11.3) are associated with Leri-Weill dyschondrosteosys (LWD) and idiopathic short stature. It has been estimated that SHOX deletions occur in 1,000–2,000 individuals in the total population, suggesting that this alteration should be investigated in all cases with unexplained short stature. SHOX deletions are currently investigated using fluorescence in situ hybridization (FISH) or molecular analysis of intragenic CA repeats. However, both techniques show some limitations. In the present study, the use of the multiple ligation probe amplification (MLPA) assay for the identification and characterization of SHOX deletions in 15 LWD patients, 3 of which carriers of chromosome abnormalities involving the SHOX gene, is reported. MLPA analysis demonstrated the heterozygous deletion of SHOX in seven patients (46.6%), disclosing the presence of two different proximal breakpoints. In patients with abnormal karyotype, MLPA analysis was able to identify the chromosomal rearrangement, showing, in addition to the SHOX deletions, the gain or loss of other genes mapped on the Xand Y chromosomes. Since MLPA analysis can be carried out on a simple buccal swab, avoiding invasive peripheral blood collection, this technique represents a fast, simple and high throughput approach in the screening of SHOX deletions, able to provide more information as compared to FISH and microsatellite analysis.

Mosaic 7q31 deletion involving FOXP2 gene associated with language impairment.

We report on a 10-year-old patient with childhood apraxia of speech (CAS) and mild dysmorphic features. Although multiple karyotypes were reported as normal, a bacterial artificial chromosome array comparative genomic hybridization revealed the presence of a de novo 14.8-Mb mosaic deletion of chromosome 7q31. The deleted region involved several genes, including FOXP2, which has been associated with CAS. Interestingly, the deletion reported here was observed in about 50% of cells, which is the first case of mosaicism in a 7q31 deletion. Despite the presence of the deletion in only 50% of cells, the phenotype of the patient was not milder than other published cases. To date, 6 cases with a deletion of 9.1-20 Mb involving the FOXP2 gene have been reported, suggesting a new contiguous gene deletion syndrome characterized mainly by CAS caused by haploinsufficiency of the genes encompassed in the 7q critical region. This report suggests that children found with a deletion involving the FOXP2 region should be evaluated for CAS and that analysis of the FOXP2 gene including array comparative genomic hybridization should be considered in selected patients with CAS. Mosaic deletions in this area may also be considered as causative of CAS.

Clustering of Y chromosome deletions in subinterval E of interval 6 supports the existence of an oligozoospermia critical region outside the DAZ gene.

Y chromosome molecular analysis was performed using the STS-PCR technique in 50 patients with oligozoospermia. Microdeletions of interval 6 of the Y chromosome were detected in seven patients, in six of whom subinterval E was affected. All patients retained the RBM1 and DAZ genes, while in one deletion involved the SPGY gene. The size of the deletion was not apparently related to the severity of the disease. These results suggest the presence of an oligozoospermia critical region on the Y chromosome within subinterval E of interval 6.