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.