Discordant sex in monozygotic XXY/XX twins: a case report

We report a case of discordant phenotypic sex in monozygotic twins mosaic 47,XXY/46,XX: monozygotic heterokaryotypic twins. The twins presented with cognitive and comprehension delay, behavioural and language disorders, all symptoms frequently reported in Klinefelter syndrome. Molecular zygosity analysis with several markers confirmed that the twins are in effect monozygotic (MZ). Array comparative genomic hybridization found no evidence for the implication of copy number variation in the phenotypes. Ultrasound scans of the reproductive organs revealed no abnormalities. Endocrine tests showed a low testosterone level in Twin 1 (male phenotype) and a low gonadotrophin level in Twin 2 (female phenotype) which, combined with the results from ultrasound examination, provided useful information for potentially predicting the future fertility potential of the twins. Blood karyotypes revealed the presence of a normal 46,XX cell line and an aneuploïd 47,XXY cell line in both patients. Examination of the chromosome constitutions of various tissues such as blood, buccal smear and urinary sediment not surprisingly showed different proportions for the 46,XX and 47,XXY cell lines, which most likely explains the discordant phenotypic sex and mild Klinefelter features. The most plausible underlying biological mechanism is a post-zygotic loss of the Y chromosome in an initially 47,XXY zygote. This would result in an embryo with both 46,XX and 47,XXY cells lines which could subsequently divide into two monozygotic embryos through a twinning process. The two cell lines would then be distributed differently between tissues which could result in phenotypic discordances in the twins. These observations emphasize the importance of regular paediatric evaluations to determine the optimal timing for fertility preservation measures and to detect new Klinefelter features which could appear throughout childhood in the two subjects.

Severe slipped capital femoral epiphysis: the Dunn's operation

INTRODUCTION

Severe slipped capital femoral epiphysis inevitably results into arthritis, making surgical recovery of normal anatomy an attractive objective. This can be achieved by the procedure described by Dunn. However, all published studies report a risk of avascular necrosis.

MATERIAL AND METHODS

The present series assembles 25 adolescent cases aged 10 to 15 years. There were 16 cases of chronic pure displacement with several months' evolution, including nine exacerbated by an acute accident. In all cases, epiphyseal slippage was severe, between 60 degrees and 90 degrees. Postoperative traction was systematic, for 15 to 21 days. As of 1979, bone scan was prescribed 2 weeks postsurgery to study femoral head vascularization.

RESULTS

Reduction was anatomic, except in two cases in which the epiphysis was fixed, respectively in caput valgum and in 15 degrees varus. There were 15 good results, with clinically and radiologically normal hips, but also 10 immediate or late complications: i.e., a complications rate of 40%. The eight immediate complications (32%) comprised four necroses (16%), two of which rapidly evolved into arthritis, three chondrolyses, which all evolved into arthritis, and one mechanical complication. At less than 10 years' FU, two arthrodeses and three hip replacements were required. At long-term FU, there were two further late deteriorations, despite initial favorable clinical and X-ray outcomes.

DISCUSSION

In theory, the procedure described by Dunn limits the vascular risk of the displacement correction. It does, however, involve certain tricky technical points: trochanterotomy may be excessive or insufficient; posterior cervical periosteal detachment may be aggressive; and the periosteum may be too tight during the reduction. In all series studying Dunn's operation, such risk of necrotic complication is reported, at rates up to 17%. The present series had a 16% rate of necrosis which, associated with chondrolysis, caused immediate loss of joint function--unacceptable, in our view, in adolescent patients. A direct approach to the displacement, after arthrotomy, with associated anterior cuneiform neck resection, corrects the slippage while avoiding the risky first two steps of Dunn's procedure, and is our current approach of choice.

[Virilizing ovarian tumors in the menopausal patient]

Virilizing ovarian tumors are rare and can occur at any age. In postmenopausal women, they commonly present with signs of masculinization. These tumors should be suspected in any patient with virilization and high testosterone levels (>1ng/mL). Tumor localization is sometimes difficult. These tumors are usually benign; surgical resection is the accepted treatment. Masculinizing consequences of hormonal secretions may be managed by cosmetologic treatments which should not be overlooked.

Breakpoint characterization: a new approach for segregation analysis of paracentric inversion in human sperm

Paracentric inversions (PAI) are structural chromosomal rearrangements generally considered to be harmless. Nevertheless, cases of viable recombinants have been reported, indicating the interest of studying the meiotic behaviour of these chromosomal abnormalities. To date, the few studies reported have been performed using either the human-hamster fertilization system or fluorescence in situ hybridization with centromeric or telomeric DNA probes. In order to improve the assessment of meiotic segregation in PAI, we present a new strategy based on the use of bacterial artificial chromosome (BAC) probes which allow a precise localization of chromosome breakpoints and the identification of all meiotic products in human sperm. Sperm samples from carriers of an inv(5) and an inv(14) were used to test this new high-resolution procedure.

[Multiple myxomata: about one case]

Among the primitive cardiac tumours, myxoma is the most common. This benign tumour is sometimes described in the context of Carney's syndrome, in which cardiac myxoma, cutaneous myxoma, lentigo and pigmentary nevus cutaneous lesions, endocrine disorders, and testicular, thyroid and hypophyseal tumours are associated. The cardiac myxomata observed are multiple, recurrent, and involve the four cardiac chambers, with a peak incidence at 25 years of age. These observations may exist in a familial context, linked to an autosomal dominant genetic factor, localized on the 17q2 chromosome with polymorphism of the PRKAR1a gene. As in the case of sporadic myxoma, rapid surgical treatment with cardio-pulmonary bypass is indicated, bearing in mind the increased risk of thromboembolic phenomena and sudden death from valvular encroachment. We report a case of bi-atrial myxoma observed in the context of Carney's syndrome.

Multicolor PRINS and multicolor PNA

Both PRimed IN Situ (PRINS) and Peptide Nucleic Acid (PNA) technologies have emerged as research techniques, but they have quickly evolved to applications in biological diagnosis assays. The two procedures now constitute efficient alternatives to the conventional fluorescence in situ hybridization (FISH) procedure for in situ chromosome identification and aneuploidy detection. They present several advantages (specificity, speed, discriminating ability) that make them very attractive for a number of cytogenetic purposes. Multicolor PRINS and PNA protocols have been described for the specific identification of human chromosomes. Various applications have already been developed in human genetics and new adaptations are ongoing.

[Osteochondritis dissecans of the femoral condyles: report of 892 cases]

PURPOSE OF THE STUDY

Osteochondritis rarely involves the femoral condyles. Discovery in this localization raises several questions concerning the nature of the articular cartilage, the potential for spontaneous healing, and, in the event of a free fragment, the outcome after its loss or repair.

MATERIAL AND METHODS

This multicentric study included 892 pediatric and adult cases, the cutoff between two series being defined by fusion of the inferior growth plate. We excluded medical or surgical osteochondritis, cases involving the patella, osteochondral fractures, juvenile polyosteochondrosis, adult osteonecrosis, and osteochondritis beginning after the age of 50 years.

RESULTS

Mean age at diagnosis was 16.5 years. Mean age at treatment onset was 22 years. Pain was the predominant symptom. 80% of cases were unilateral and 70% involved the medial condyle. The anatomic lesions were different in adults, showing more advanced degradation. At diagnosis, Bedouelle stages Ia and IIb constituted 80% of the cases observed among children while in adults, 66% were Bedouelle stages IIb to IV. Outcome was very good for the majority of children with Hughston clinical stage 4 while half of the x-rays were Hughston stage 3 and 4. There were thus a large percentage of children with abnormal xrays whose disease history was not yet terminated. In the adult series, the percentages of Hughston 3 and 4 was about the same as clinically. The x-rays were rarely perfectly normal since half of the clinical stage 3 patients were noted in stage 4. An abnormal x-ray with a very good clinical presentation was observed in a very large proportion of patients.

DISCUSSION

It is difficult to interpret the plain x-ray and identify patients with a potentially unfavorable prognosis. We defined three radiographic classes: defect, nodule and empty notch. The Bedouelle classification uses information from all available explorations, particularly MRI and arthroscopy. Numerous therapeutic methods are used. Interruption of sports activities is the first intention treatment for children. Data in the literature and the findings of this symposium do not demonstrate any beneficial effect of immobilization on healing compared with simple abstention from sports activities. Transchondral perforation is a simple operation with low morbidity. In 85% of cases, it was used for lesions with an intact joint cartilage considered stable in 96% of cases. Healing was achieved in six months for 48% if the growth plate had not fused. The fragment was fixed in 43% of the cases with a loose cartilage fragment. Outcome was fair but degraded with the state of the joint cartilage and thus the stability of the fragment. Fixation must stabilize the fragment but not prevent further consolidation via osteogenesis. This is why deep perforations are drilled beyond the ossified area and additional osteochondral grafts are used. The Wagner operation gives less satisfactory results than more complicated procedures. Removal of a sequestrum is a simple, minimally invasive procedure with an uneventful postoperative period, but in the long term it favors osteoarthritic degradation, especially when performed in adults. Mosaic grafts give good mid term results. Morbidity is low especially if the grafts are harvested above the notch. The question of chondrolysis around the grafts was beyond the scope of this study. Chondrocyte grafting is difficult to accomplish and is expensive. The mid term results are good for large lesions. Osteotomy is logical only in the event of early stage osteoarthritic degradation. DECISION ALGORITHM IN CHILDREN AND ADOLESCENTS: If the plain x-ray reveals a defect (class I), simple interruption of sports activities should be proposed. Two situations can then develop. First, in a certain number of patients, the pain disappears as the defective zone ossifies progressively. Complete cure is frequent before the age of 12 years. In the second situation, the knee remains painful and the x-ray does not change or worsens to a class II nodular formation. In this case an MRI must be obtained to determine whether the joint cartilage is normal. There are two possibilities. First, the osteochondral fragment is viable and most probably will become completely re-integrated, particularly if the lesion is far from the growth plate. Necrosis is the other possibility. Transchondral perforations are needed in this case. If on the contrary the cartilage is altered, there is little hope for spontaneous cure. Arthroscopy may be needed to complete the exploration. Fragments, especially if there is a large surface area, must be fixed. Perforations to favor revascularization are certainly useful here. In the last situation (class III), the fragment wobbles on a thin attachment or has already fallen into the joint space. This is the type of problem generally observed in adults. The decision algorithm in adults is the same as in children for the rare nodular aspects (class II). There could be a discussion between transcartilage perforation and fixation. If there are a large number of fragments, fixation may not be fully successful and the lesion might be considered class III. For class III lesions, three operations can be used: removal of the sequestrum, mosaic bone-cartilage grafts, or autologous chondrocyte grafts. At the same follow-up, mosaic grafts give better results than excision of sequestra. It may be useful to remove sequestra in a limited number of situations: if there is just a small area of osteochondritis, the lesion is old and partially healed, or the zone is non weight-bearing. For other lesions, we favor mosaic grafts. We still do not have enough follow-up to assess the long-term outcome with these mosaic grafts, but simple excision clearly favors osteoarthritic degradation. Can chondrocytes grafts be compared with mosaic grafts? Chondrocyte grafts have been used for very large lesions and have given results similar to mosaic grafts. It might also be possible to combine fixation of a loose fragment and a mosaic graft. LESSONS FROM THIS STUDY: 1) The prognosis of osteochondritis is better before than after fusion of the growth plate but the lesion does not always heal in children. 2) Presence of osteochondritis requires complementary anatomic and functional exploration to determine the stability and the vitality of the fragment. 3) Attention must be taken to perform transchondral perforations early enough, particularly in children. 4) Screw fixation is not always sufficient. The trophicity of the fragment and its blood supply must be improved. 5) Mosaic grafts are preferable to excision of the fragment. 6) Chondrocyte grafts will be more widely used in the future.

Rare Robertsonian translocations and meiotic behaviour: sperm FISH analysis of t(13;15) and t(14;15) translocations: a case report

t(13;15) and t(14;15) are two rare Robertsonian translocations. Meiotic segregation was studied in four males heterozygous for the rare Robertsonian translocations t(13;15) and t(14;15). Both locus-specific probes (LSPs) and whole chromosome painting (WCP) probes, specific to chromosomes 13, 14 and 15, were used in this study. The number of spermatozoa scored for each carrier ranged from 891 to 5000. The frequencies of normal and balanced sperm resulting from the alternate mode of segregation ranged from 77.6 to 92.8%, confirming the prevalence of alternate segregation over other segregation modes in all Robertsonian translocations. The incidences of unbalanced complements ranged from 6.7 to 20.4%, with a significant excess of disomy rates over the complementary frequencies of nullisomy. This variability might reflect differences in the location of breakpoints in translocated chromosomes, leading to the variable production of unbalanced gametes and the variable alterations of semen parameters in Robertsonian translocation carriers.

[Management of Lagrange and Rigault stage IV extension type supracondylar fracture of the humerus in children]

PURPOSE OF THE STUDY

Lagrange and Rigault stage IV extension type supracondylar fracture of the humerus (Gartland and Wilkins type III) involves major displacement, making treatment difficult. Several therapeutic methods have been described but indications vary considerably between teams. We conducted a retrospective analysis in order to evaluate the results of different methods, identify the most adapted technique, and detail the conditions necessary for good results with the collar and cuff immobilization method described by Blount.

MATERIAL AND METHODS

Forty-four children (30 boys and 14 girls), mean age seven years six months, were treated between January 1990 and December 2001. The collar and cuff immobilization technique was used for sixteen children (including four who underwent open revision for early secondary displacement), percutaneous pinning for two, and open crossed pinning for thirty (including four who developed secondary displacement after collar and cuff immobilization). One out of two collar and cuff treatments was instituted within six hours of injury. The four secondary displacements after collar and cuff immobilization treatment occurred after fracture reduction more than six hours after injury. The proportion of open reductions increased with longer delay to reduction after injury. Mean immobilization was three and a half weeks. The Flynn criteria were used to assess outcome at mean seven years eight months follow-up.

RESULTS

Outcome was satisfactory in all children treated with definitive collar and cuff immobilization and by percutaneous pinning; the rate was 97% after open procedures (persistent sequelae of radial palsy in one child).

DISCUSSION

Early treatment before six hours increased the chances of success with the collar and cuff method which remains the technique of choice for Lagrange and Rigault stage IV extension type supracondylar fractures. In the event of failure or complications, other classical methods should be discussed, including percutaneous pinning or direct access for open osteosynthesis.

[Percutaneous rotational osteoclasis in management of congenital radio-ulnar synostosis]

PURPOSE OF THE STUDY

Congenital radio-ulnar synostosis blocks the wrist in a position of more or less pronounced pronation. The degree of pronation and possible bilateral involvement can compromise upper limb function. We propose percutaneous osteoclasis of the antebrachial skeleton to remedy this situation

PATIENTS AND METHODS

We performed 12 percutaneous rotation osteoclasis procedures. The objective was to weaken the metaphysodiaphyseal cortical periosteum of one or both of the forearm bones by intermittent perforations. This enabled derotation of the wrist which was maintained for six to eight weeks in a brachiopalmar cast.

RESULTS

Mean correction of pronation was 51 degrees. There were no cases of vascular or nervous complications and healing was uneventful. The esthetic outcome was very satisfactory.

DISCUSSION

Surgery is not indicated for all cases of synostosis. We retain for surgery patients presenting pronation at 60 degrees or more. At this degree of pronation, function is greatly compromised in adolescence, particularly if there is a bilateral involvement. Compared with other techniques, percutaneous osteoclasis is a simple safe and reliable technique. Reoperation is not required to remove material. The procedure is easier in young children, preferably at the age of 3 to 7 years, before the development of a functional handicap.

Meiotic segregation of rare Robertsonian translocations: sperm analysis of three t(14q;22q) cases

BACKGROUND

The t(14;22) remains one of the rare Robertsonian translocations observed in human, with an occurrence estimated at 1.2%. Three cases of rare Robertsonian translocation t(14;22) were investigated for meiotic segregation in sperm samples from male carriers using the fluorescent in situ hybridization (FISH) procedure. The three carriers included two men with an abnormal semen analysis and one with normal semen parameters.

METHODS

Both locus-specific probes and whole-chromosome painting probes, specific for chromosomes 14 and 22, were used in this study. The number of spermatozoa scored for each probe set ranged from 3279 to 10,024.

RESULTS

In the three carriers, similar frequencies, ranging from 78.53 to 81.76%, were found for normal and balanced spermatozoa resulting from alternate segregation. The total proportion of unbalanced spermatozoa resulting from adjacent modes of segregation ranged from 17.59 to 20.94%.

CONCLUSION

This finding confirmed the predominance of alternate segregation over other segregation types in all Robertsonian translocations and indicates a higher production of imbalances in the t(14;22) than in most of the Robertsonian translocations previously analysed. This could be related to the variable location of breakpoints in Robertsonian translocations. This breakpoint diversity could also play a role in the differences in reproductive status observed in male carriers of Robertsonian translocations.

Capsulorraphie dans les instabilités volontaires de l’épaule

PURPOSE OF THE STUDY

Chronic shoulder instability is uncommon in patients with an immature skeleton. Some of these pediatric patients can produce their dislocation voluntarily raising the question of the traumatic or constitutional nature of the condition as well as its direction and tolerance. We report our experience with 29 patients.

MATERIAL AND METHOD

Over a period of 28 years, 29 children aged 5 to 15 years were treated for voluntary shoulder dislocation. The dislocation was painful and poorly tolerated in 19, affecting daily life and sports activities. Posterior dislocation was observed in 15 patients and anterior dislocation in 4, but the direction was not always easy to establish, particularly in children with ligament laxity; multiple directions were not uncommon. Rehabilitation for at least eight months did not relieve pain in 11 patients who had a sensation of a blocked, unreliable shoulder which could not be controlled voluntarily. Posterior capsulorrhaphy was performed in 8 patients and anterior capsulorrhaphy in 3.

RESULTS

Mean follow-up was 8 years. At last follow-up, all shoulders were stable and shoulder motion was normal with no loss of function. More than half of the children had resumed sports activities. Capsulorrhaphy was proposed when the pre-operative explorations did not reveal any bone or rim anomaly. The only preoperative finding in the operated patients was increased capsule volume, particularly in the inferior portion. Intraoperatively, ulceration of the humeral cartilage was found in two patients. Anatomic reconstruction of the capsuloligamentary structures enabled recovery of passive stability and active stability of the scapulohumeral joint, preventing further voluntary dislocation.

Ultra-rapid multicolor PRINS protocol for chromosome detection in human sperm

We report a new multicolor PRINS procedure for chromosome identification on human sperm. Based on the direct in-situ mixing of the colors of the fluorochromes (FITC, TRITC, Cascade Blue) incorporated in sequential PRINS reactions, this method facilitates rapid distinct labeling of 3 or 4 chromosomes. Each PRINS reaction consists of a unique 4 minute step for annealing and elongation. The method was successfully tested on lymphocytes and spermatozoa. Estimates of disomy were performed for chromosomes 7, 9 and 16 on sperm samples from 2 healthy donors. There was no significant difference between the disomy rates obtained with the conventional two-color PRINS technique and this new three-color procedure. By simplifying the multicolor PRINS protocol, this new protocol should facilitate the use and adaptation of PRINS to various cytogenetic applications.

Neurological presentation of three patients with 22q11 deletion (CATCH 22 syndrome)

Chromosome 22q11 deletion (CATCH 22 syndrome or velocardiofacial syndrome) is one of the most frequent chromosomal syndromes. Neurological features other than cognitive disorders are probably the least-described part of the expanding phenotype of the 22q11 deletion. We report the neurological features of three unrelated children with a de novo deletion: one patient with an autistic disorder, a second patient with hypocalcaemic neonatal seizures and unusual persistent epileptic focus at electroencephalographic follow-up, and a third patient with atypical absence epilepsy. These observations enlarge the clinical and neurological spectrum of the 22q11 deletion. Awareness of such cases is necessary, and a diagnosis of the 22q11 deletion should be suspected in children with common neurological features associated with severe or mild dysmorphism. Diagnosis of the 22q11 deletion should be confirmed by fluorescence in situ hybridization analysis associated with standard chromosomal analysis.

[Primary thyroid lymphoma: report of 8 cases]

PURPOSE

Primary thyroid lymphoma (PTL) is a rare disease. Few patients are reported in the literature. We report eight new cases of PTL with long-term follow-up.

RESULTS

The clinical presentation was usually an enlarging neck mass squeezing surrounding structures. The diagnosis was established after thyroidectomy with histopathologic and immunohistochemical studies. Histology showed infiltrates of chronic lymphocytic thyroiditis in all cases. Three patients had thyroid lymphoma arising from mucosa-associated lymphoid tissue. One patient died postoperatively. The other seven were treated with combined chemotherapy and radiotherapy. They were still in remission after a 6-year follow-up.

CONCLUSION

Diagnosis of PTL should be suspected when there is a recent thyroid enlargement. Surgery associated with chemotherapy and radiation gave good results in our study with long-term follow-up, though surgery was not always recommended in previous reports.

Study of the occurrence of interchromosomal effect in spermatozoa of chromosomal rearrangement carriers by fluorescence in-situ hybridization and primed in-situ labelling techniques

The possibility that a chromosomal rearrangement might disturb the meiotic behaviour of chromosomes not involved in the rearrangement and favour non-disjunction is a controversial issue in human cytogenetics. Using two-colour fluorescence in-situ hybridization and primed in-situ labelling techniques, we have investigated the segregation pattern of 10 chromosomes (chromosomes 1, 4, 9, 13, 15, 16, 20, 21, X and Y) in spermatozoa from nine carriers of balanced structural rearrangements and three normal men. The patients were divided into two groups according to their semen parameters. In rearrangement carriers and normal subjects, sex chromosomes and chromosome 21 displayed a higher rate of disomy than the other chromosomes. No evidence for the occurrence of interchromosomal effect was found in the spermatozoa of fertile rearrangement carriers, but significant variations were observed for all chromosomes tested in the group of infertile translocation carriers, suggesting a direct correlation between poor quality spermatozoa and increased aneuploidy rate in this group. In fertile carriers of chromosomal rearrangements, the occurrence of non-disjunction of chromosomes not involved in the rearrangement might therefore be considered as fortuitous, whereas in infertile carriers, the risk for interchromosomal effect appears to be real and should be taken into consideration in the genetic counselling of infertile couples with a male partner carrying a chromosomal rearrangement.

Diabetes insipidus revealing acute myelogenous leukaemia with a high platelet count, monosomy 7 and abnormalities of chromosome 3: a new entity?

We describe three cases of acute myeloid leukaemia revealed by diabetes insipidus. The patients were 42, 38 and 39 yr old and they had marked hyperleukocytosis, circulating immature granular cells and a normal or elevated platelet count. The leukaemia was type AML-M2 according to the FAB classification. Cytogenetic studies showed inversion of chromosome 3 (q21;q26) in 2 cases and a translocation (3;3)(q21;q29?) in the remaining case, both associated with monosomy 7. All the cerebral CT scans were normal. Complete remission was never achieved, and all three patients survived less than 14 months. Desmopressin therapy was active but treatment could not be reduced. The association of dysmegakaryopoiesis with a chromosome 3 abnormality and diabetes insipidus is probably not fortuitous and could represent a new entity.

[Application of the PRINS technique for chromosome examination in fetal cells present in maternal blood]

Both detection and chromosomal analysis of fetal cells present in the maternal circulation can be performed using Histopaque double density gradient centrifugation followed by primed in situ (PRINS) labeling technique. This approach has been tested on blood samples from 15 pregnant women and 6 control donors with primers specific for chromosomes 9, X and Y. The cell separation technique allows recovery of both mononuclear cells and polynuclear cells with a 97% efficiency. PRINS labeling was successful in 100% cells from control blood samples. Among patient samples, 2 "false-negative" results were observed. These preliminary results suggest that the present protocol might be efficient for non-invasive prenatal chromosome analysis.

Fetal cells in maternal blood: the use of primed in situ (PRINS) labelling technique for fetal cell detection and sex assessment

Prenatal diagnosis is presently performed following invasive procedures with variable risks of fetal loss; non-invasive procedures using fetal cells in maternal blood would be welcome for the early detection of fetal sex or aneuploidy. We describe a simple and rapid protocol to detect fetal cells and thus to assess fetal sex. In a first step, nucleated blood cells were separated into mononuclear and polynuclear cells using a double density gradient centrifugation. In a second step primed in situ (PRINS) labelling technique was performed to label Y-chromosomes. 15 samples were studied and correct gender assignment was made in 13/15. The number of labelled nuclei was higher in polynuclear cell phases than in mononuclear cell phases. Moreover, the polylobular aspect of labelled nuclei from polynuclear cell phases strongly suggested that they could belong to fetal polynuclear cells. The PRINS technique combines some advantages of FISH, such as visual assessment of in situ chromosome labelling and the powerful specificity and sensitivity of PCR. In association with a simple enrichment procedure it constitutes a rapid protocol for fetal cell detection, non-invasive early prenatal sex assessment, and could further be applied to detect the main viable aneuploidies.

Cytogenetic analysis of meiotic segregation in sperm from two males heterozygous for reciprocal translocations using PRINS and humster techniques

The meiotic segregation patterns of 2 reciprocal translocations t(7;9)(q33;p21) and t(7;18)(q35;q11) were analyzed in sperm of 2 heterozygote carriers. Both sperm karyotyping and in situ PRINS labeling of sperm nuclei were performed on a sperm sample from each subject. Using the humster technique, 54 and 72 sperm chromosome complements were successfully analyzed for the t(7;9) and the t(7;18) respectively. The frequencies of alternate, adjacent 1, adjacent 2 and 3:1 segregations were 44.44%, 37.04%, 12.96% and 5.56% for the t(7;9) and 33.33%, 43.05%, 19.45% and 4.17% for the t(7;18). The PRINS procedure allowed the rapid screening of large samples of spermatozoa. However, alternate and adjacent 1 segregants were not discriminated because of the generation of centromeric signals. The segregation pattern was determined on 10,658 spermatozoa for the t(7;9) and 10,462 for the t(7;18). The distributions of segregants were similar to those obtained by sperm karyotyping. These data were pooled with results from 37 reciprocal translocations previously studied by sperm karyotyping and 6 recently investigated by FISH. The analysis of these compiled data demonstrates the particularity of the production of imbalances in male gametes; independent of the predisposition for a type of imbalance at term, there is a preferential production of adjacent 1 imbalance in sperm.

[Vitamin-resistant rickets cured by removal of a bone tumor. Review of the literature]

PURPOSE OF THE STUDY

Rickets secondary to bone or soft tissue tumors are rare in children. Majority of the reported cases occurred in adults older than thirty. This entity can be cured after tumor removal. The authors present a case in a ten year boy and literature review.

MATERIAL

A ten year boy complained of diffuse bone and muscle weakness for two years. A diagnosis of arthritis was made but the patient continued to complain. Serum calcium level was normal (2.33 mmol/l), phosphorus was very low (0.43 mmol/l), serum alkaline phosphatase was high, parathyroid hormone and vitamin D level were normal. Urinalysis showed abnormal phosphate excretion.

METHODS

The absence of malabsorption, no family history of rickets or hypophosphatermy presence of a marked excess of urinary phosphate, very low serum phosphate and normal serum calcium, vitamin D and parathyroid hormone levels led us to consider a diagnosis of tumor induced osteomalacia. Radiographs showed a large round radiolucent lesion in the left superior pubic ramus and generalized demineralisation.

RESULTS

We performed a complete tumor resection and the space was filled with bone graft. On histopathologic examination it was a benign mesenchymal tumor. Rapid reversal of biochemical anomalies, radiographs anomalies and clinical manifestation were observed after complete tumor resection.

DISCUSSION

The authors have described the tumor, the osteomalacia and the pathogenesis of tumor rickets. Histologically the most common causative tumors were vascular tumors, mesenchymal tumors and non ossifying tumors. The tumor were of bone or soft tissue origin. Clinical symptoms were muscular weakness, bone and muscle pain. Biochemically there is a very low phosphate level, a normal serum calcium level as well as a normal vitamin D and PTH level. There is a significant high level of urinal phosphate. The mechanism proposed to explain oncogenic osteomalacia includes tumor secretion of phosphaturic substance other than PTH and calcitonin. Another hypothesis is a substance interfering with normal vitamin D metabolism. The pathogenesis is not clearly defined.

CONCLUSION

Regardless to the mechanism of osteomalacia, complete removal of the tumor will cure the patient. A diligent search for tumors should be done in patients with vitamin D resistant rickets.

Incidence of chromosome 1 disomy in human sperm estimated by the primed in situ (PRINS) labeling technique

The primed in situ (PRINS) labeling technique was used to determine the rate of disomy of chromosomes 1 and 16 in sperm of two normal subjects. Two different but specific primers (alpha-satellite and satellite II) for chromosome 1 were used in parallel experiments to test the efficiency of PRINS labeling in sperm nuclei. A minimum of 10,000 sperm nuclei per chromosome primer was analyzed, leading to a total number of 41,651 scored spermatozoa. Similar rates of chromosome 1 disomy (mean values, 0.18% and 0.20%) were found in both donors when the alpha-satellite and satellite II primers were used, demonstrating the reliability of PRINS labeling on sperm nuclei. For chromosome 16, the disomy rate among the two donors ranged from 0.20% to 0.24%. This study confirms that PRINS provides a rapid and efficient method for in situ chromosomal screening of sperm nuclei.

Preimplantation embryo chromosome analysis by primed in situ labeling method

OBJECTIVE

To present the use of primed in situ labeling method in preimplantation diagnosis.

DESIGN

Double- and triple-primed in situ labeling were performed on 10 morphologically abnormal preimplantation embryos, using combinations of specific primers for chromosomes 9, 13, 16, 18, 21, X, and Y.

SETTING

Embryos were obtained from patients at the Montpellier University Hospital.

PATIENT(S)

Seven women undergoing IVF at the Montpellier University Hospital.

INTERVENTION(S)

Isolated interphase nuclei from poor quality preimplantation embryos were prepared for primed in situ labeling technique.

MAIN OUTCOME MEASURE(S)

Numerical abnormalities assessed by primed in situ labeling analysis.

RESULT(S)

Using directly fluorescent-labeled nucleotides, the labeling reaction for three chromosomes did not exceed 2.30 hours. Only three analyzed embryos appeared to be chromosomally normal. Mosaicism, aneupoidy, and haploidy were observed in the seven other embryos.

CONCLUSION(S)

The primed in situ labeling method offers a simple and reliable screening tool for gender determination and aneuploidy detection. The use of this technique may contribute to significantly improve the procedure of preimplantation diagnosis.

Rapid chromosome detection in human gametes, zygotes, and preimplantation embryos using the PRINS technique

PURPOSE

The analysis of the chromosomal constitution of human gametes and embryos is of particular importance for investigation of aneuploidy occurrence and diagnostic purposes. The PRINS method constitutes an alternative to FISH for in situ chromosomal identification. We have adapted this method to human gametes, zygotes, and preimplantation embryos.

RESULTS

Chromosome-specific labeling was obtained in gametes, zygotes, and isolated blastomeres. Simultaneous detection of two or three chromosomes can be completed in less than 3 hr using fluorochrome-labeled nucleotides.

CONCLUSIONS

The PRINS technique appears to be more efficient than FISH for detection and discrimination of alpha-satellite DNA sequences. The present study demonstrates the usefulness of PRINS for chromosomal screening and preimplantation diagnosis.

Aneuploidy detection in human sperm nuclei using PRINS technique

Rapid and specific identification of chromosomes can be attained in situ using the PRimed IN Situ (PRINS) labelling technique. We have adapted this technique to mature human sperm in combination with a protocol for simultaneous decondensation and denaturation of sperm nuclei. This strategy allowed us to obtain double labelling of human spermatozoa in a < 2-hr reaction. In the present study, we report the estimates of disomy for chromosomes 3, 7, 10, 11, and 17 on 64,642 spermatozoa from 2 normal males. The incidences of disomy ranged from 0.28-0.34%. There were no significant interindividual or interchromosomal differences in disomy rates.

Prenatal aspects of giant fetal cranial haemangio-endothelioma

A case of a large vascular lesion of the skull is reported. The lesion was discovered at 22 weeks' gestation and it rapidly increased in size, reaching 8 cm a month later. Tumor echogenicity was the same as that for soft tissues and colour Doppler examination revealed intense vascularization. Cordocentesis showed features of the Kasabach-Merritt syndrome and very high plasma levels of alpha-fetoprotein. A Caesarean section was performed to avoid dystocia and led to the birth of a baby with cardiac failure in the immediate neonatal period. Biopsies of the mass led to the diagnosis of a non-malignant haemangio-endothelioma. The mass was removed and plastic surgery performed. The baby is alive and well 9 months after the operation.

The PRINS technique: potential use for rapid preimplantation embryo chromosome screening

The primed in-situ labelling (PRINS) method is an alternative to in-situ hybridization for chromosomal detection based on the use of chromosome-specific oligonucleotide primers. Using this process, we have developed a simple and semi-automatic method for rapid in-situ detection of human chromosomes. The reaction was performed on a programmable temperature cycler. Specific labelling was obtained in < 2 h reaction. Double PRINS techniques were performed on six morphologically abnormal preimplantation embryos using primers specific for chromosomes 9, 16, 18, 21, X and Y. The majority of these embryos displayed chromosomal abnormalities. The present results demonstrate that PRINS may be a simple and reliable technique applicable in human preimplantation diagnosis.

Interest of umbilical fold incision for pyloromyotomy

We report the results of a study concerning 80 infants undergoing a pyloromyotomy over a 3-and-a-half-year period. 40 infants had a right upper quadrant transverse rectus incision and 40 infants had an umbilical fold incision. Morbidity and cosmetic aspect of the two techniques were compared. We insist on the umbilical fold incision which presents the same advantages as the classic one and a better cosmetic result.

Molecular studies of translocations and trisomy involving chromosome 13

Twenty-four cases of trisomy 13 and one case with disomy 13, but a de novo dic(13,13) (p12p12) chromosome, were examined with molecular markers to determine the origin of the extra (or rearranged) chromosome. Twenty-one of 23 informative patients were consistent with a maternal origin of the extra chromosome. Lack of a third allele at any locus in both paternal origin cases indicate a somatic duplication of the paternal chromosome occurred. Five cases had translocation trisomy: one de novo rob(13q14q), one paternally derived rob(13q14q), two de novo t(13q13q), and one mosaic de novo t(13q13q)/r(13). The patient with a paternal rob(13q14q) had a maternal meiotic origin of the trisomy; thus, the paternal inheritance of the translocation chromosome was purely coincidental. Since there is not a significantly increased risk for unbalanced offspring of a t(13q14q) carrier and most trisomies are maternal in origin, this result should not be surprising; however, it illustrates that one cannot infer the origin of translocation trisomy based on parental origin of the translocation. Lack of a third allele at any locus in one of the three t(13q13q) cases indicates that it was most likely an isochromosome of postmeiotic origin, whereas the other two cases showed evidence of recombination. One balanced (nontrisomic) case with a nonmosaic 45, -13, -13, +t(13;13) karyotype was also investigated and was determined to be a somatic Robertsonian translocation between the maternal and paternal homologues, as has been found for all balanced homologous Robertsonian translocations so far investigated. Thus, it is also incorrect to assume in de novo translocation cases that the two involved chromosomes are even from the same parent. Despite a maternal origin of the trisomy, we cannot therefore infer anything about the parental origin of the chromosomes 13 and 14 involved in the translocation in the de novo t(13q14q) case nor for the two t(13;13) chromosomes showing a meiotic origin of the trisomy.

FISH and PRINS, a strategy for rapid chromosome screening: application to the assessment of aneuploidy in human sperm

The co-utilization of FISH and PRINS techniques for in situ chromosome screening was tested on human sperm nuclei. We used a centromeric repeat probe specific for chromosome 4 for FISH. PRINS reactions were performed with alpha-satellite primers specific for either chromosomes 9 or chromosome 18. Double labeling was obtained and estimates of disomy rates were carried out for the three chromosomes.

Rapid in situ detection of chromosome 21 by PRINS technique

The "PRimed IN Situ labeling" (PRINS) method is an interesting alternative to in situ hybridization for chromosomal detection. In this procedure, chromosome labeling is performed by in situ annealing of specific oligonucleotide primers, followed by primer elongation by a Taq polymerase in the presence of labeled nucleotides. Using this process, we have developed a simple and semi-automatic method for rapid in situ detection of human chromosome 21. The reaction was performed on a programmable temperature cycler, with a chromosome 21 specific oligonucleotide primer. Different samples of normal and trisomic lymphocytes and amniotic fluid cells were used for testing the method. Specific labeling of chromosome 21 was obtained in both metaphases and interphase nuclei in a 1 hour reaction. The use of oligonucleotide primer for in situ labeling overcomes the need for complex preparations of specific DNA probes. The present results demonstrate that PRINS may be a simple and reliable technique for rapidly detecting aneuploidies.

PRINS as a method for rapid chromosomal labeling on human spermatozoa

Direct in situ labeling of human spermatozoa was performed using the PRINS method. This technique is based on annealing of specific oligonucleotide primers, and subsequent primer extension by a Taq DNA polymerase. The reaction was carried out on a programmable temperature cycler, and labeling was obtained in a 1-hr reaction. The method was successfully tested with specific primers for chromosomes 13, 16, and 21. This suggests that PRINS may be a fast and reliable technique for detecting aneuploidies.

Amniocentesis before 15 weeks' gestation: technical aspects and obstetric risks

In a prospective case-control study, early amniocenteses (EAC, n = 242) at between 12 and 14 weeks gestation, were compared with standard amniocenteses (SAC, n = 242) performed at between 15 and 24 weeks gestation. The medical records of these 484 cases were reviewed for indications, success rate, color and volume of amniotic fluid, gestational age, number of needle insertions, location of the placenta, culture failure rate, obstetric complications and therapeutic abortion rate. There were no significant differences between the two groups in success rate, in culture success rate or in the outcome of the pregnancies. The volume of the sample taken was smaller in the EAC patients (P < 0.001), and therapeutic abortions were performed significantly earlier (P < 0.02.) Results show that EAC is feasible from 11 weeks' gestation, and can be performed for the usual indications as an alternative to chorionic villus sampling. In the near future, cytogenetic techniques will enable results to be obtained in less than a week.

Use of the primed in situ labelling (PRINS) technique for a rapid detection of chromosomes 13, 16, 18, 21, X and Y

The primed in situ labelling (PRINS) technique is an alternative to in situ hybridization for chromosomal screening. We have developed a semi-automatic PRINS protocol, using a programmable thermocycler. The method has been successfully tested with specific primers for chromosomes, 13, 16, 18, 21, X and Y. Specific chromosome detection has been obtained on both metaphases and interphase nuclei. This suggests that PRINS may be a reliable technique for detecting aneuploidies and some chromosomal aberrations.

Selection of chromosome-specific primers and their use in simple and double PRINS techniques for rapid in situ identification of human chromosomes

The PRimed IN Situ labeling (PRINS) technique is an alternative to in situ hybridization for rapid chromosome screening. We have defined and tested new specific oligonucleotide primers for alpha-satellite DNA of several chromosomes. When using a semiautomatic PRINS protocol, specific labeling was obtained in both metaphase cells and interphase nuclei in a 1-h reaction. PRINS may be a simple and reliable technique for rapidly detecting aneuploidies.