Identification of t(15;17) and a segmental duplication of chromosome 11q23 in a patient with acute myeloblastic leukemia M2

A 32-year-old man was newly diagnosed with acute myelocytic leukemia, classified as acute myeloblastic leukemia with maturation (AML-M2) according to the French-American-British classification system. Conventional chromosome analysis before chemotherapy treatment revealed an abnormal karyotype: a possible segmental duplication of 11q23, plus a translocation between chromosomes 15 and 17 [t(15;17) (q22;q21.1)] in the majority of cells analyzed. Fluorescence in situ hybridization analysis using commercially available probes confirmed the cytogenetic findings. To our knowledge, this is the first report of a combination of t(15;17) and a segmental duplication of 11q23 in a patient with AML-M2.

Duplication 15q as the sole anomaly in an acute promyelocytic leukemia patient without t(15;17)

We present a unique chromosomal abnormality found in a patient with acute myeloblastic leukemia of French-American-British subtype M3. The patient was referred for an evaluation of a chromosomal anomaly exclusively associated with FAB M3 or acute promyelocytic leukemia: a translocation between chromosomes 15 and 17, t(15;17)(q22;q21.1). Neither t(15;17) nor rearrangement of RARalpha was detected by routine G-banded chromosome as well as fluorescence in situ hybridization analysis using the commercial dual-color PML/RARalpha translocation probe and the RARalpha probe, a break apart rearrangement dual-color probe. Instead of the typical rearrangement between chromosomes 15 and 17, all cells analyzed had a duplication of the segment of chromosome 15 between bands 15q15 and 15q26.

[Cancer in siblings of children with cancer]

INTRODUCTION

In some rare inherited disorders, such as Li-Fraumeni syndrome, relatives of children with cancer are at increased risk of cancer. We aimed to assess relations between childhood cancer and sibling risk, and evaluate the influence of recessive conditions in cancer causation.

MATERIAL AND METHODS

We did a population-based cohort study in the Nordic countries of 42,277 siblings of 25,605 children with cancer. Children with cancer were identified from records in the five Nordic cancer registries, and their siblings from nationwide population registries. Cancers in siblings were documented through record linkage with cancer registries and compared with national incidence rates. We also assessed cancer incidence in parents to identify familial cancer syndromes.

RESULTS

284.2 cancers were expected in siblings, whereas 353 were diagnosed (standardised incidence ratio 1.24 95% CI, 1.12-1.38). Risk ratios for siblings were highest in the first decade of life (2.59; 1.89-3.46). We excluded 56 families with genetic syndromes linked to cancer, which reduced this ratio from 1.7 to 1.0 (0.7-1.3) for siblings younger than 20 years and from 1.3 to 1.0 (0.8-1.3) for those aged 20-29 years. We found no new patterns of familial cancer that indicated inherited susceptibility, or evidence that recessive conditions might contribute to cancers not explained by syndromes. 40% of cancers in siblings that occurred before age 20 years could be attributed to known genetic factors, whereas 60% remained unexplained.

DISCUSSION

Apart from rare cancer syndromes, paediatric cancer is not an indicator of increased risk in siblings.

Medium chain acyl coenzyme A dehydrogenase (MCAD) deficiency: the case for screening all newborns

Medium chain acyl coenzyme A dehydrogenase (MCAD) deficiency is the most common inborn error of fatty acid oxidation with a frequency of 1 in 12,000, an estimated four new cases in the state of Oklahoma each year. The first clinical manifestation is a hypoglycemic episode any time between the newborn period to adulthood. Largely due to failure of diagnosis, the first episode can be lethal, with a frequency of early mortality of 25%. We report a child with MCAD deficiency admitted to the OU Medical Center-Children's Hospital to illustrate the molecular basis, clinical features, and management of the disorder and to present the pros and cons of instituting newborn screening in our state. Such screening is already part of routine newborn metabolic screening in four states. In Oklahoma and elsewhere, there is current discussion, which we summarize, on whether or not to include MCAD deficiency in the routine neonatal screening program. We suggest the evidence says, "Start now."

Study design and cohort characteristics of the Childhood Cancer Survivor Study: a multi-institutional collaborative project

BACKGROUND

Increased attention has been directed toward the long-term health outcomes of survivors of childhood cancer. To facilitate such research, a multi-institutional consortium established the Childhood Cancer Survivor Study (CCSS), a large, diverse, and well-characterized cohort of 5-year survivors of childhood and adolescent cancer.

PROCEDURE

Eligibility for the CCSS cohort included a selected group of cancer diagnoses prior to age 21 years between 1970-1986 and survival for at least 5 years.

RESULTS

A total of 20,276 eligible subjects were identified from the 25 contributing institutions, of whom 15% are considered lost to follow-up. Currently, 14,054 subjects (69.3% of the eligible cohort) have participated by completing a 24-page baseline questionnaire. The distribution of first diagnoses includes leukemia (33%), lymphoma (21%), neuroblastoma (7%), CNS tumor (13%), bone tumor (8%), kidney tumor (9%), and soft-tissue sarcoma (9%). Abstraction of medical records for chemotherapy, radiation therapy, and surgical procedures has been successfully completed for 98% of study participants. Overall, 78% received radiotherapy and 73% chemotherapy.

CONCLUSION

The CCSS represents the largest and most extensively characterized cohort of childhood and adolescent cancer survivors in North America. It serves as a resource for addressing important issues such as risk of second malignancies, endocrine and reproductive outcome, cardiopulmonary complications, and psychosocial implications, among this unique and ever-growing population.

Rapid prenatal diagnosis of trisomies 13, 18, 21 and sex chromosome anomalies by fluorescence in situ hybridization: a year's experience

The present paper summarizes our first 12 months' experiences of rapid prenatal diagnosis using commercially available diagnostic fluorescence in situ hybridization (FISH) probes for chromosomes X, Y, 13, 18 and 21. The data clearly demonstrate that the advantage of using FISH as an adjunct technique is the fast and reliable determination of the common fetal chromosomal aneuploidies; the results are available in less than 24 hours instead of the 7-14 days with standard techniques.

Duplication 15q in a patient with t(8;21) acute myeloblastic leukemia (M2)

We present unique chromosomal abnormalities found in a patient with acute myeloblastic leukemia (AML) of French-American-British subtype M2. The patient was referred for an evaluation of chromosomal anomaly associated with AML. She was found to have an abnormal karyotype 46,XX,t(8;21)(q22;q22), and a questionable dup(15)(q15q22) in the majority of cells analyzed. Two cells had the same chromosomal anomalies plus a duplicated derivative chromosome 21 [der(21)t(8;21)(q22;q22)]. These cytogenetic findings were confirmed by fluorescence in situ hybridization utilizing the appropriate DNA probes. To our knowledge, this is the first case report of a combination of the translocation between chromosomes 8 and 21, a duplication of chromosome 15 [dup(15)(q15q22), and a duplicated derivative chromosome 21 [der(21)t(8;21)(q22;q22)].

Cancer in siblings of children with cancer in the Nordic countries: a population-based cohort study

BACKGROUND

In some rare inherited disorders such as Li-Fraumeni syndrome, relatives of children with cancer are at increased risk of cancer. We aimed to assess relations between childhood cancer and sibling risk, and evaluate the influence of recessive conditions in cancer causation.

METHODS

We did a population-based cohort study in the Nordic countries of 42277 siblings of 25605 children with cancer. Children with cancer were identified from records in the five Nordic cancer registries, and their siblings from nationwide population registries. Cancers in siblings were documented through record linkage with cancer registries and compared with national incidence rates. We also assessed cancer incidence in parents to identify familial cancer syndromes.

FINDINGS

284.2 cancers were expected in siblings, whereas 353 were diagnosed (standardised incidence ratio 1.24 95% CI 1.12-1.38). Risk ratios for siblings were highest in the first decade of life (2.59, 1.89-3.46). We excluded 56 families with genetic syndromes linked to cancer, which reduced this ratio from 1.7 to 1.0 (0.7-1.3) for siblings younger than 20 years, and from 1.3 to 1.0 (0.8-1.3) for those aged 20-29 years. We found no new patterns of familial cancer that indicated inherited susceptibility, or evidence that recessive conditions might contribute to cancers not explained by syndromes. 40% of cancers in siblings that occurred before age 20 years could be attributed to known genetic factors, whereas 60% remained unexplained.

INTERPRETATION

Apart from rare cancer syndromes, paediatric cancer is not an indicator of increased cancer risk in siblings.

Pharmacogenetics, race, and ethnicity: social identities and individualized medical care

Social categories such as race and ethnicity have long been used in interpreting patient symptoms, diagnosing disease, and predicting therapeutic response. DNA-based diagnostic tests and pharmacogenetic screens could make these uses of social categories largely irrelevant by allowing clinicians to base diagnosis and treatment decisions on the unique genetic features of individual patients. Despite this attractive vision of individualized care, however, social categories are likely to continue playing a significant role in the coming era of genetic medicine. Current uses of social categories in pharmacogenetic research, for example, illustrate how drug development and marketing will perpetuate the use of social categories such as race and ethnicity. Those uses may unintentionally blunt the precision of genetic technologies and pose new threats to socially identifiable populations. These implications suggest the need for greater caution in using social categories as indicators for specific tests or therapies and for federal legislation to protect against discriminatory uses of individuals' genetic information. In addition, more precise social classifications than those presently in use may allow us to realize the full potential of DNA-based technologies, thus minimizing social disparities in health care. Those more precise social classifications should reflect extended patient pedigrees and not the self-reported claims of racial and/or ethnic affiliation.

Single nucleotide polymorphism in prohibitin 3' untranslated region and breast-cancer susceptibility

The RNA encoded by the 3' untranslated region of the prohibitin gene arrests cell proliferation by blocking the transition between the G1 and S phases of the cell cycle. The product of a variant allele (T allele) is inactive. We did a case-control study of prohibitin genotype in 205 women with breast cancer and 1046 healthy controls. The results showed an association between the T allele and breast cancer in women who reported a first-degree relative with the disease (odds ratio 2.5, p=0.005). An even stronger association was found in a subset of women diagnosed at or before age 50 years (4.8, p=0.003). These data suggest that prohibitin genotyping has value in assessing risk of breast cancer in women aged 50 years or younger with at least one first-degree relative with the disease.

Inheritance of pancreatic cancer in pancreatic cancer-prone families

Families are being increasingly recognized as carrying an inherited susceptibility for pancreatic cancer, apparently unrelated to any currently recognized syndrome. The authors provide a review of the current evidence for familial susceptibility to pancreatic cancer. A formal segregation analysis of the pattern of inheritance of pancreatic cancer in 70 families from the National Registry for Familial Pancreatic Cancer is described. This analysis suggests a single major gene with an autosomal dominant mode of inheritance controlling susceptibility for pancreatic cancer in these families.

The variable penetrance and spectrum of manifestations of multiple endocrine neoplasia type 1

BACKGROUND

Some experts maintain that (1) > 90% of patients with multiple endocrine neoplasia type 1 (MEN1) are first seen with hyperparathyroidism (HPTH) so that routine screening for other features is unnecessary and (2) MEN1 has > or = 94% penetrance by age 50 years.

METHODS

We constructed a regional registry of patients with or at risk for MEN1 and examined phenotypic profiles in 34 patients. MEN1 was defined as (1) endocrinopathy of 2 of the 3 principal related tissues (parathyroid, gastrointestinal endocrine, pituitary) or (2) 1 such feature plus a first-degree relative with MEN1.

RESULTS

The initial feature of MEN1 was HPTH in 50%, pituitary tumor in 18%, and gastrointestinal endocrine tumor in 32% of patients, with overall incidences of 82%, 65%, and 74%, respectively. HPTH developed by age 50 years in 73% of patients and by age 70 years in 83%. Penetrance of MEN1 at age 50 years was 82%. Associated features included renal (1) and rectal (1) cancer, malignant thymic carcinoid (1), and malignant pheochromocytoma (1).

CONCLUSIONS

Expression of MEN1 can vary considerably from established patterns. In our geographic region HPTH does not routinely precede other features of MEN1 and cannot be used to distinguish affected patients among those at risk. MEN1 can be inapparent until late in life and may be significantly underdiagnosed.

Permanent Committee of the International Congress of Human Genetics

For over three decades, the Permanent Committee of the International Congresses of Human Genetics has served the purpose of selecting a host and site for the quadrennial Congress, which is due next in 2001. The Committee has statutes and consists of one voting representative from 38 nations and other ex officio members, much like the General Assembly of the United Nations. It meets twice during each International Congress, otherwise conducting its business by mail and telecommunication. Its structure could be the beginnings of a truly global democratic body of human geneticists to address other issues and to serve other purposes, as human genetics becomes increasingly international, as inevitably it must.

Surgical management of spinal cord compression from plexiform neurofibromas in patients with neurofibromatosis 1

OBJECTIVE

Plexiform neurofibromas with sizable intraspinal extensions and resultant spinal cord compromise pose challenging management problems, because these lesions may involve multiple nerves and engulf adjacent vascular and visceral structures. In this report, we review our experience with the surgical treatment of these lesions.

METHODS

Patients were identified by a detailed review of hospital medical records and the database of our multidisciplinary neurofibromatosis clinic. Ten patients had large plexiform neurofibromas that extended intraspinally, producing a combination of myelopathy and radiculopathy. Two patients exhibited single-level intraspinal growth, and eight showed multilevel involvement. Four patients showed bilateral plexiform neurofibromatous growth intraspinally, with "hourglass" compression of the spinal cord. Operative approaches and outcomes were reviewed in detail.

RESULTS

Gross total resection of the symptomatic intraspinal tumor component was achieved for nine patients. The management of the extraspinal component was individualized, depending on the pattern and extent of involvement of the surrounding structures. Nine patients experienced complete recovery of neurological function postoperatively; the remaining patient demonstrated significant functional improvement. With a median follow-up period of 4 years, only one patient has developed recurrent intraspinal compression, in this case from tumor involvement by the same plexiform lesion at a lower spinal level. Two patients treated early in the series using standard laminectomy approaches developed significant kyphotic deformities, necessitating subsequent fusion. Based on these initial results, osteoplastic laminotomy techniques were used in the last five cases, allowing anatomic reconstruction of the involved levels; none of these latter patients has developed significant kyphosis, with a median follow-up period of 3 years.

CONCLUSION

Radical resection of intraspinal tumor components in patients with neurofibromatosis 1 and large plexiform neurofibromas can help to preserve excellent neurological function. Technical factors in the management of these lesions are presented.

Familial eosinophilia: clinical and laboratory results on a U.S. kindred

We describe a five-generation kindred with familial eosinophilia (FE; MIM131400), characterized by the occurrence of sustained eosinophilia of unidentifiable cause in multiple relatives. The inheritance pattern is consistent with an autosomal dominant pattern. Among 52 related subjects studied, 19 were affected and 33 were unaffected. Ten unaffected spouses were also evaluated. Four subjects with sustained eosinophilia were diagnosed with cardiac abnormalities and two of them also had neurologic symptoms. In comparison with the unaffected or spouses, evaluation of complete blood counts showed that the affected relatives had, as expected, significantly higher white cell (P < 0.005) and absolute eosinophil counts (P < 0.001) and lower red cell counts (P < 0.05). Evaluation of serum cytokine levels (IL-5, IL-3, and granulocyte-macrophage colony-stimulating factor (GMCSF) and serology for parasitic helminth infection demonstrated no differences between the affected and unaffected individuals; no individuals studied had serologic evidence for parasitic infection. There were also no differences in anti-nuclear antibody, serum cobalamin (vitamin B12) level, immunoglobulin level, leukocyte alkaline phosphatase, rheumatoid factor, HLA analysis, and stool findings for ova and parasites. Among eight affected persons who had peripheral blood or bone marrow karyotype analysis, two carried the same chromosome abnormality, a pericentric inversion of chromosome 10, inv (10) (p11.2q21.2). A gene mapping study is currently underway to study the underlying genetic mechanism(s) of this syndrome.

Genetic disease in offspring of long-term survivors of childhood and adolescent cancer

Numerous case series have addressed the concern that cancer therapy may damage germ cells, leading to clinical disease in offspring of survivors. None has documented an increased risk. However, the methodological problems of small series make it difficult to draw firm conclusions regarding the potential of cancer treatments to damage the health of future offspring. We conducted a large interview study of adult survivors of childhood cancer treated before 1976. Genetic disease occurred in 3.4% of 2,198 offspring of survivors, compared with 3.1% of 4,544 offspring of controls (P=.33; not significant); there were no statistically significant differences in the proportion of offspring with cytogenetic syndromes, single-gene defects, or simple malformations. A comparison of survivors treated with potentially mutagenic therapy with survivors not so treated showed no association with sporadic genetic disease (P=.49). The present study provides reassurance that cancer treatment using older protocols does not carry a large risk for genetic disease in offspring conceived many years after treatment. With 80% power to detect an increase as small as 40% in the rate of genetic disease in offspring, this study did not do so. However, we cannot rule out the possibility that new therapeutic agents or specific combinations of agents at high doses may damage germ cells.

Spectrum of malignancy and premalignancy in Carney syndrome

Carney syndrome is a rare, autosomal dominant, multi-system disorder comprising 8 well-characterized findings, only 2 of which need be present for a definitive diagnosis. Benign neoplasms are frequent, but malignancies are thought to be uncommon. We have studied a family to clarify the diagnosis and spectrum of clinical manifestations of the syndrome and to develop guidelines for management. The proposita, a 34-year-old woman had classic findings of Carney syndrome, invasive follicular carcinoma of the thyroid gland, Barrett metaplasia of the esophagus, neoplastic colonic polyps, bipolar affective disorder, and atypical mesenchymal neoplasm of the uterine cervix distinct from the myxoid uterine leiomyoma usually seen in this syndrome. Although thyroid gland neoplasm is rare in Carney syndrome, this patient's most aggressive manifestation was her thyroid carcinoma. The diagnosis of Carney syndrome was established in her 9-year-old son and is a probable diagnosis in her 12-year-old daughter. Endocrine manifestations were prominent in the family with at least 9 relatives in 3 generations affected with various endocrine abnormalities. The findings in this family indicate that the spectrum of manifestations in this pleiotropic gene apparently includes a malignant course with premalignant and endocrinologic disorders not previously recognized.

Prenatal diagnosis: update addresses technological advances

This is the second in a series of articles provided to the readers of PENNSYLVANIA MEDICINE as an update from researchers and clinicians in this cutting-edge medical field. The series is partially sponsored through a grant from the Pennsylvania Department of Health to the University of Pittsburgh Department of Human Genetics.