Recurrent fetal cystic hygroma with normal chromosomes: case report and review of the literature.

Recurrence of fetal cystic hygroma in subsequent pregnancies is extremely rare. A review of the literature to date revealed only two other reports of recurrence with normal fetal karyotypes documented in at least two of the affected pregnancies. At 11 weeks' gestation, the fetus of a 19-year-old gravida 3 para 0 was discovered to have a large cystic hygroma. Subsequent evaluation during the second trimester revealed increasing size of the septated nuchal mass and ascites. A 46,XX fetal karyotype was noted in her two prior pregnancies, both of which had also been complicated by the development of cystic hygroma and nonimmune hydrops. Cystic hygroma, associated with a normal karyotype, can be inherited as an autosomal recessive trait.

Successful pregnancy outcome in a woman with a gain-of-function mutation of the calcium-sensing receptor. A case report.

BACKGROUND: Gain-of-function mutations of the calcium-sensing receptor gene have recently been identified as a cause of familial hypercalciuric hypocalcemia. There have been no earlier reported cases of pregnancy among patients with this disorder. CASE: A 26-year-old woman, gravida 1, para 0, was diagnosed at age 18 as being a heterozygous carrier of a mutation in the calcium-sensing receptor gene. Stable maternal hypocalcemia was achieved during pregnancy with high-dose calcium and 1,25-dihydroxyvitamin D3 therapy. Prenatal diagnosis was accomplished via amniocentesis at 16 weeks' gestation. The patient underwent cesarean delivery at 35 5/7 weeks' gestation after developing the HELLP syndrome. CONCLUSION: Patients with mutations of the calcium-sensing receptor may have a successful pregnancy outcome. This abnormality may be transmitted to the fetus via an autosomal dominant pattern.

Chromosome duplications and deletions and their mechanisms of origin.

Duplications and deletions of the same gene loci or chromosome regions are known to produce different clinical manifestations and are significant factors in human morbidity and mortality. Extensive cytogenetic and molecular cytogenetic studies with cosmid and YAC probes in two patients with unique mosaicism for reciprocal duplication-deletion allowed us to further understand the origin of these abnormalities. The first patient's mosaic karyotype was 46,XX, inv dup(11) (q23q13)/46,XX,del(11)(q13q23). The second patient had a 46,XY,dup(7)(p11.2p13)/46,XY,del(7)(p11.2p13)/46,XY karyotype. Fluorescence in situ hybridization studies on the first patient placed the two breakpoints near the folate-sensitive fragile sites FRA11A and FRA11B. The presence of repeated sequences responsible for these fragile sites may have been involved in the patient's duplication-deletion. Our investigation leads us to conclude that, in addition to known mechanisms (such as unequal crossovers between homologs, unequal sister chromatid exchanges, excision of intrachromatid loops, and meiotic recombination within a single chromatid), duplication-deletion can also arise by the formation of an overlying loop followed by an uneven crossover at the level of the DNA strand.

Pregnancy complicated by multiple endocrine neoplasia type IIA (Sipple's syndrome).

A patient with preexisting multiple endocrine neoplasia type IIA had normal 24-hour urinary metanephrine and vanillylmandelic acid excretions before and during pregnancy. After a benign prenatal course, the patient had a term spontaneous vaginal delivery. Multiple endocrine neoplasia type IIA antedating pregnancy may be associated with a normal obstetric outcome in the absence of a phenochromocytoma.

Teaching efficacy of a medical education module on genetic testing for cancer.

BACKGROUND: With the identification of the breast cancer susceptibility genes BRCA1 and BRCA2, clinical testing for detection of the mutated genes may be available in the near future. Primary care physicians increasingly serve as full-service providers and gatekeepers and must be aware of presymptomatic testing in order to counsel their patients appropriately. To address this educational need, a new module was incorporated into the genetics course taken by first-year medical students at the Medical College of Virginia. METHODS: The module used small groups, led by genetics faculty and members of the Virginia Breast Cancer Foundation, for discussion of case examples. The medical students' knowledge of and attitudes toward cancer and predictive genetic testing were assessed by a pretest and a posttest. RESULTS: After the module, knowledge scores increased by 27%, and significant changes were seen in the students' attitudes toward issues such as the regulation of testing availability and the psychological effect of testing. Most students consistently felt that predictive genetic testing is beneficial, that they would have the testing themselves, that genetic counseling should be required for testing, and that insurers' access to genetic testing results should be limited. Overall, the module was received favorably by all participants. CONCLUSIONS: Small-group discussion of relevant case examples increases knowledge and awareness of issues regarding presymptomatic genetic testing for breast cancer.