Severe combined immunodeficiency (SCID): from the detection of a new mutation to preimplantation genetic diagnosis

PURPOSE

To describe the identification of a new mutation responsible for causing human severe combined immunodeficiency syndrome (SCID). In a large consanguineous Israeli Arab family, this served as a diagnostic tool and enabled us to carry out preimplantation genetic diagnosis (PGD). We also demonstrated that PGD for homozygosity alleles is feasible.

METHODS

We carried out genome-wide screening followed by fine mapping and linkage analysis in order to identify the candidate genes. We then sequenced DCLRE1C in order to find the familial mutation. The family was anxious to avoid the birth of an affected child, and therefore, because of their religious beliefs, PGD was the only option open to them. The embryos were biopsied at day 3, and a single blastomere from each embryo was analyzed by multiplex polymerase chain reaction for the SCID mutation and 5 additional polymorphic markers flanking DCLRE1C.

RESULTS

Linkage analysis revealed linkage to chromosome 10p13, which harbors the DNA Cross-Link Repair Protein 1 C (DCLRE1C) ARTEMIS gene. Sequencing identified an 8 bp insertion in exon 14 (1306ins8) of DCLRE1C in all the affected patients; this causes an alteration in amino acid 330 of the protein from cysteine to a stop codon (p.C330X). One cycle of PGD was performed and two embryos were transferred, one homozygous wild-type and one a heterozygous carrier, and healthy twins were born.

CONCLUSIONS

Identifying the familial mutation enabled us to design a reliable and accurate PGD protocol, even in this case of a consanguineous family.

Blastocyst culture and transfer: lessons from an unselected, difficult IVF population

Blastocyst-stage transfer has yielded excellent results in good prognosis IVF patients, but its efficacy in the general IVF population has not been clearly demonstrated. The objective of this study was to compare cleavage-stage and blastocyst-stage transfer in a mixed, general IVF population. In a prospective, quasi-randomized study, 152 patients underwent 164 treatment cycles. Patients were allocated to cleavage-stage (group 1; n = 94) or blastocyst-stage (group 2; n = 70) transfer. Main outcome measures included implantation, clinical pregnancy and live birth rates. Implantation (11.2% versus 15.5%), clinical pregnancy (34% versus 21%) and live birth rates per transfer (21.3% versus 13.8%) and per started cycle (21.3% versus 11.4%) were all comparable for groups 1 and 2, respectively. Logistic regression analysis revealed that blastocyst culture and transfer reduced the odds for pregnancy in the general IVF population and defined a good prognosis group for blastocyst transfer. Introducing blastocyst culture and transfer to all IVF patients is not advantageous. Blastocyst transfer should be offered primarily to good prognosis patients, and this group should be specifically defined in each clinical set-up.

Follicular growth and development under continuous gonadotropin-releasing hormone antagonist administration

OBJECTIVE

Ovarian follicle and cyst formation have been recognized as an advance phenomenon associated with GnRH agonist administration. With the use of GnRH antagonists, pituitary suppression is immediate and no flare effect and follicle growth are expected. We describe two patients who developed a dominant follicle and presumably ovulated in response to hCG triggering under continuous sole administration of a GnRH antagonist.

DESIGN

Case report.

SETTING

An IVF unit at a university hospital.

PATIENT(S)

Two young healthy female patients undergoing IVF because of male-factor infertility.

INTERVENTION(S)

Continuous daily administration of a GnRH antagonist from menstruation with the aim of achieving ovarian suppression.

MAIN OUTCOME MEASURE(S)

Endocrine and ultrasound characteristics of follicular growth.

RESULT(S)

Both patients developed a dominant follicle under sole administration of a GnRH antagonist, accompanied by a gradual rise in serum estradiol and endometrial thickness which culminated in a spontaneous LH surge. Ovulation was triggered by hCG and mid-luteal progesterone levels were suggestive of ovulation.

CONCLUSION(S)

We describe for the first time the development of a dominant follicle and presumable ovulation under continuous administration of a GnRH antagonist. Serum gonadotropin concentrations indicate that the pituitary failed to suppress in both patients. The exact mechanism of this phenomenon remains to be elucidated.

Timing intra-Fallopian transfer procedures

With the gradual decline in the use of zygote intra-Fallopian transfer (ZIFT), current practice is to offer ZIFT almost exclusively to patients with repeated implantation failure (RIF). For practical reasons, the procedure is sometimes deferred by 1 day and embryo intra-Fallopian transfer (EIFT) is performed. The aim of the present study was to compare the reproductive outcome of ZIFT versus EIFT. In a retrospective analysis, 176 patients who failed in 7.65 +/- 3.7 previous IVF cycles underwent 200 ZIFT and 73 EIFT procedures. Implantation and live birth rates were compared for both groups. Patients in both groups were found comparable for demographic and clinical parameters. Similar numbers of oocytes were retrieved and fertilized in both groups, and 5.2 +/- 1.2 zygotes/embryos were transferred. Implantation and live birth rates (10.5 and 26.5% versus 10.9 and 24.7% for ZIFT and EIFT respectively) were comparable. It is concluded that tubal transfer of zygotes and day-2 cleavage stage embryos are equally effective.

Vaginal delivery following caesarean section-the use of oxytocin and prostaglandins

Five hundred and twenty women with one previous caesarean section underwent a trial of labour in our department during the past five years. They were divided into three groups-those receiving oxytocin, those receiving prostaglandins, and those unstimulated who had spontaneous labour. The obstetric outcomes were compared. Rates of vaginal delivery in the three groups were 65%, 67% and 72%, respectively. No mother died and there were no cases of complete uterine rupture. Our results confirm similar reports that vaginal delivery after a previous caesarean section can be safely achieved in about two-thirds of patients. Serious complications are minimal when the use of oxytocin and prostaglandins is carefully monitored.

Conversion of laparoscopy to laparotomy due to adnexal malignancy

PURPOSE

The purpose of the present report was to assess the conversion rate from laparoscopy to laparotomy due to adnexal malignancy and to identify factors that might assist in the selection of the appropriate operative approach in patients with suspicious adnexal masses.

METHODS

A retrospective review of the medical records of women who underwent laparoscopy due to ultrasonically complex adnexal masses. Ninety-five consecutive patients fulfilling these criteria, were identified. A comparison of patients with benign tumors who had laparoscopy only to those with invasive malignancies in whom laparoscopy was converted to laparotomy was performed.

RESULTS

Malignancy was diagnosed in 18 (18.9%) patients. In 13 patients with malignancy (two borderline and 11 invasive), comprising 72.2% of the malignancies and 13.7% of the total group with complex adnexal masses, the laparoscopy was converted to laparotomy. Age of more than 50 years and a serum CA125 level above 35 U/ml were significantly more common in the malignant than in the benign group (90.9% vs. 15.6% and 63.6% vs. 11.6%, respectively; p < 0.0001 and p < 0.003, respectively). When both factors were present, the sensitivity and specificity for malignancy were 73.3% and 93.2%, respectively, and the positive and negative predictive values 73.3% and 95.6%, respectively.

CONCLUSION

When an ultrasonically complex adnexal mass is encountered, predictive factors for malignancy should be taken into account before the mode of intervention is chosen. The conversion from laparoscopy to laparotomy because of an invasive malignant tumor is acceptable, if it is performed immediately and a gynecologic oncologist is on stand-by.

Congenital cytomegalovirus infection: a long-standing problem still seeking a solution

OBJECTIVE

The purpose of this study was to review the accuracy of current tests used for the diagnosis of in utero cytomegalovirus infection and to discuss the potential value of preconceptional and postconceptional screening programs for prevention of congenital infection.

STUDY DESIGN

A computer-assisted search was performed for relevant English language publications between 1987 and 1994. We identified 119 cases of suspected intrauterine cytomegalovirus infection in which either amniotic fluid or fetal blood had been analyzed antenatally.

RESULTS

Congenital cytomegalovirus infection affects 0.5% to 2.5% of all newborns. The rate of transmission to the fetus after primary infection during pregnancy ranges from 15% to 50%. Of the fetuses infected in utero, 10% exhibit congenital cytomegalovirus syndrome. Evaluation of 119 cases of suspected infection has shown that polymerase chain reaction and cultures of amniotic fluid are the most reliable tests for prenatally determining the presence of viral particles. However, efficacy of routine antenatal screening in reducing the rate of fetal disease is limited.

CONCLUSION

It is concluded that at present the accuracy of tests used for the diagnosis of in utero cytomegalovirus infection is undetermined. Serologic screening of all pregnant women is of limited value and at present is not recommended.

Premature delivery of small versus appropriate-for-gestational-age neonates. A comparative study of maternal characteristics

Prematurity and growth retardation of the fetus are major factors affecting perinatal outcome. The purpose of this study was to compare maternal characteristics of 63 women who delivered a preterm, small-for-gestational-age (SGA) neonate with those of 63 women matched for parity and gestational age who delivered a preterm, appropriate-for-gestational-age (AGA) neonate. All women delivered at the Soroka Medical Center between January 1, 1985, and December 31, 1990. Mothers of SGA neonates were more likely than those of AGA neonates to be over the age of 35 years (P = .043), to have hypertensive disorders and oligohydramnios (P < .001), to have induced labor (P < .001) and to deliver by cesarean section (P < .001). In addition, they had a higher rate of morbidity in the puerperium (P = .015) and were more likely to have longer hospitalization (P = .002). In contrast, previous preterm deliveries were significantly more common in the AGA group than in the SGA group (P = .034). The results of this study indicate that women who deliver preterm SGA neonates belong to a special subgroup with unique characteristics in comparison to those who deliver preterm AGA neonates.