Coarctation of the aorta. Long-term follow-up and prediction of outcome after surgical correction

The long-term clinical course was studied in 646 patients, who underwent isolated operative repair of coarctation of the aorta at the Mayo Clinic from 1946 to 1981. There were 17 perioperative deaths, and 58 patients were lost to follow-up. Of the 571 patients with long-term follow-up, 11% required subsequent cardiovascular surgery, and 25% developed hypertension. There were 87 late deaths. The mean age at death was 38 years (range, 0-67 years). Estimated survival analysis revealed 91% of patients alive at 10, 84% at 20, and 72% at 30 years after operative repair. The most common cause of late death was coronary artery disease in 32 patients, followed by sudden death, heart failure, cerebrovascular accidents, and ruptured aortic aneurysm. Age, sex, and postoperative systolic blood pressure were found to be independently predictive of survival. For patients less than 14 years of age at the time of initial coarctectomy, survival to 20 years was 91%, and for patients 14 years or older at the time of operation, survival was 79%. The best survivorship was observed in patients operated on at 9 years of age or less. The higher the postoperative systolic pressure, the higher the probability of death. This study has the largest population undergoing repair of coarctation of the aorta with a median follow-up of as long as 20 years. Four main points emerged. 1) Age at the time of initial repair is the most important predictor of long-term survival. Surgery should be offered to patients after age 1 year or sooner if hypertension is severe. 2) Coronary artery disease is the most common cause of late death.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for a genetic basis for hyperandrogenemia in polycystic ovary syndrome

Our preliminary family studies have suggested that some female first-degree relatives of women with polycystic ovary syndrome (PCOS) have hyperandrogenemia per se. It was our hypothesis that this may be a genetic trait and thus could represent a phenotype suitable for linkage analysis. To investigate this hypothesis, we examined 115 sisters of 80 probands with PCOS from unrelated families. PCOS was diagnosed by the combination of elevated serum androgen levels and Collapse

Key Words Collapse

MESH Headings

• Adolescent
• Adult
• Child
• Female
• Genetic Linkage
• Genetic Predisposition to Disease
• Humans
• Hyperandrogenism/genetics
• Middle Aged
• Polycystic Ovary Syndrome/genetics

Collapse

Grants

• M01 RR010732 NCRR NIH HHS
• MO1 RR10732 NCRR NIH HHS
• R01 DK40605 NIDDK NIH HHS
• R01 DK040605 NIDDK NIH HHS
• U54 HD034449 NICHD NIH HHS
• KO8 HD0118 NICHD NIH HHS

Collapse

Collaborators Collapse

Chromosome 22-specific low copy repeats and the 22q11.2 deletion syndrome: genomic organization and deletion endpoint analysis

The 22q11.2 deletion syndrome, which includes DiGeorge and velocardiofacial syndromes (DGS/VCFS), is the most common microdeletion syndrome. The majority of deleted patients share a common 3 Mb hemizygous deletion of 22q11.2. The remaining patients include those who have smaller deletions that are nested within the 3 Mb typically deleted region (TDR) and a few with rare deletions that have no overlap with the TDR. The identification of chromosome 22-specific duplicated sequences or low copy repeats (LCRs) near the end-points of the 3 Mb TDR has led to the hypothesis that they mediate deletions of 22q11.2. The entire 3 Mb TDR has been sequenced, permitting detailed investigation of the LCRs and their involvement in the 22q11.2 deletions. Sequence analysis has identified four LCRs within the 3 Mb TDR. Although the LCRs differ in content and organization of shared modules, those modules that are common between them share 97-98% sequence identity with one another. By fluorescence in situ hybridization (FISH) analysis, the end-points of four variant 22q11.2 deletions appear to localize to the LCRs. Pulsed-field gel electrophoresis and Southern hybridization have been used to identify rearranged junction fragments from three variant deletions. Analysis of junction fragments by PCR and sequencing of the PCR products implicate the LCRs directly in the formation of 22q11.2 deletions. The evolutionary origin of the duplications on chromosome 22 has been assessed by FISH analysis of non-human primates. Multiple signals in Old World monkeys suggest that the duplication events may have occurred at least 20-25 million years ago.

Frequency of 22q11 deletions in patients with conotruncal defects

OBJECTIVES

This study was designed to determine the frequency of 22q11 deletions in a large, prospectively ascertained sample of patients with conotruncal defects and to evaluate the deletion frequency when additional cardiac findings are also considered.

BACKGROUND

Chromosome 22q11 deletions are present in the majority of patients with DiGeorge, velocardiofacial and conotruncal anomaly face syndromes in which conotruncal defects are a cardinal feature. Previous studies suggest that a substantial number of patients with congenital heart disease have a 22q11 deletion.

METHODS

Two hundred fifty-one patients with conotruncal defects were prospectively enrolled into the study and screened for the presence of a 22q11 deletion.

RESULTS

Deletions were found in 50.0% with interrupted aortic arch (IAA), 34.5% of patients with truncus arteriosus (TA), and 15.9% with tetralogy of Fallot (TOF). Two of 6 patients with a posterior malalignment type ventricular septal defect (PMVSD) and only 1 of 20 patients with double outlet right ventricle were found to have a 22q11 deletion. None of the 45 patients with transposition of the great arteries had a deletion. The frequency of 22q11 deletions was higher in patients with anomalies of the pulmonary arteries, aortic arch or its major branches as compared to patients with a normal left aortic arch regardless of intracardiac anatomy.

CONCLUSIONS

A substantial proportion of patients with IAA, TA, TOF and PMVSD have a deletion of chromosome 22q11. Deletions are more common in patients with aortic arch or vessel anomalies. These results begin to define guidelines for deletion screening of patients with conotruncal defects.

Prevalence of 22q11 microdeletions in DiGeorge and velocardiofacial syndromes: implications for genetic counselling and prenatal diagnosis

Deletions of chromosome 22q11 have been seen in association with DiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS). In the present study, we analysed samples from 76 patients referred with a diagnosis of either DGS or VCFS to determine the prevalence of 22q11 deletions in these disorders. Using probes and cosmids from the DiGeorge critical region (DGCR), deletions of 22q11 were detected in 83% of DGS and 68% of VCFS patients by DNA dosage analysis, fluorescence in situ hybridisation, or by both methods. Combined with our previously reported patients, deletions have been detected in 88% of DGS and 76% of VCFS patients. The results of prenatal testing for 22q11 deletions by FISH in two pregnancies are presented. We conclude that FISH is an efficient and direct method for the detection of 22q11 deletions in subjects with features of DGS and VCFS as well as in pregnancies at high risk for a deletion.

Thirty-seven candidate genes for polycystic ovary syndrome: strongest evidence for linkage is with follistatin

Polycystic ovary syndrome (PCOS) is a common endocrine disorder of women, characterized by hyperandrogenism and chronic anovulation. It is a leading cause of female infertility and is associated with polycystic ovaries, hirsutism, obesity, and insulin resistance. We tested a carefully chosen collection of 37 candidate genes for linkage and association with PCOS or hyperandrogenemia in data from 150 families. The strongest evidence for linkage was with the follistatin gene, for which affected sisters showed increased identity by descent (72%; chi(2) = 12.97; nominal P = 3.2 x 10(-4)). After correction for multiple testing (33 tests), the follistatin findings were still highly significant (P(c) = 0.01). Although the linkage results for CYP11A were also nominally significant (P = 0.02), they were no longer significant after correction. In 11 candidate gene regions, at least one allele showed nominally significant evidence for population association with PCOS in the transmission/disequilibrium test (chi(2) >/= 3.84; nominal P < 0.05). The strongest effect in the transmission/disequilibrium test was observed in the INSR region (D19S884; allele 5; chi(2) = 8.53) but was not significant after correction. Our study shows how a systematic screen of candidate genes can provide strong evidence for genetic linkage in complex diseases and can identify those genes that should have high (or low) priority for further study.

Deletions and microdeletions of 22q11.2 in velo-cardio-facial syndrome

Velo-cardio-facial syndrome (VCFS), an autosomal dominant disorder, is characterized by cleft palate, cardiac defects, learning disabilities and a typical facial appearance. Less frequently, VCFS patients have manifestations of the DiGeorge complex (DGC) including hypocalcemia, hypoplastic or absent lymphoid tissue and T-cell deficiency suggesting that these 2 conditions share a common pathogenesis. Here, we report the results of cytogenetic and molecular studies of 15 VCFS patients. High-resolution banding techniques detected an interstitial deletion of 22q11.21-q11.23 in 3 patients. The remaining 12 patients had apparently normal chromosomes. Molecular analysis with probes from the DiGeorge Chromosome Region (DGCR) within 22q11 detected DNA deletions in 14 of 15 patients. In 2 families, deletions were detected in the affected parent as well as the propositus suggesting that the autosomal dominant transmission of VCFS is due to segregation of a deletion. Deletions of the same loci previously shown to be deleted in patients with DGC explains the overlapping phenotype of VCFS and the DGC and supports the hypothesis that the cause of these two disorders is the same.

Selection and treatment of candidates for heart transplantation. A statement for health professionals from the Committee on Heart Failure and Cardiac Transplantation of the Council on Clinical Cardiology, American Heart Association

Improved outcome of heart failure in response to medical therapy, coupled with a critical shortage of donor organs, makes it imperative to restrict heart transplantation to patients who are most disabled by heart failure and who are likely to derive the maximum benefit from transplantation. Hemodynamic and functional indexes of prognosis are helpful in identifying these patients. Stratification of ambulatory heart failure patients by objective criteria, such as peak exercise oxygen consumption, has improved ability to select appropriate adult patients for heart transplantation. Such patients will have a poor prognosis despite optimal medical therapy. When determining the impact of individual comorbid conditions on a patient's candidacy for heart transplantation, the detrimental effects of each condition on posttransplantation outcome should be weighed. Evaluation of patients with severe heart failure should be done by a multidisciplinary team that is expert in management of heart failure, performance of cardiac surgery in patients with low left ventricular ejection fraction, and transplantation. Potential heart transplant candidates should be reevaluated on a regular basis to assess continued need for transplantation. Long-term management of heart failure should include continuity of care by an experienced physician, optimal dosing in conventional therapy, and periodic reevaluation of left ventricular function and exercise capacity. The outcome of high-risk conventional cardiovascular surgery should be weighed against that of transplantation in patients with ischemic and valvular heart disease. Establishment of regional specialized heart failure centers may improve access to optimal medical therapy and new promising medical and surgical treatments for these patients as well as stimulate investigative efforts to accelerate progress in this critical area.

Human steroidogenic acute regulatory protein: functional activity in COS-1 cells, tissue-specific expression, and mapping of the structural gene to 8p11.2 and a pseudogene to chromosome 13

Steroidogenic acute regulatory protein (StAR) appears to mediate the rapid increase in pregnenolone synthesis stimulated by tropic hormones. cDNAs encoding StAR were isolated from a human adrenal cortex library. Human StAR, coexpressed in COS-1 cells with cytochrome P450scc and adrenodoxin, increased pregnenolone synthesis > 4-fold. A major StAR transcript of 1.6 kb and less abundant transcripts of 4.4 and 7.5 kb were detected in ovary and testis. Kidney had a lower amount of the 1.6-kb message. StAR mRNA was not detected in other tissues including placenta. Treatment of granulosa cells with 8-bromo-adenosine 3',5'-cyclic monophosphate for 24 hr increased StAR mRNA 3-fold or more. The structural gene encoding StAR was mapped using somatic cell hybrid mapping panels to chromosome 8p. Fluorescence in situ hybridization placed the StAR locus in the region 8p11.2. A StAR pseudogene was mapped to chromosome 13. We conclude that StAR expression is restricted to tissues that carry out mitochondrial sterol oxidations subject to acute regulation by cAMP and that StAR mRNA levels are regulated by cAMP.

Phenotype of the 22q11.2 deletion in individuals identified through an affected relative: cast a wide FISHing net!

PURPOSE

The chromosome 22q11.2 deletion has been identified in the majority of patients with DiGeorge syndrome, velocardiofacial syndrome, and conotruncal anomaly face syndrome and in some patients with the autosomal dominant Opitz G/BBB syndrome and Cayler cardiofacial syndrome. In addition, 22q11.2 deletion studies are becoming part of a standardized diagnostic workup for some isolated defects such as conotruncal cardiac anomalies and velopharyngeal incompetence. However, there is little information available on the clinical findings of unselected patients. For example, those individuals identified during prenatal diagnosis, as part of a generalized screening protocol, or following the diagnosis in a relative. This information will be invaluable in defining the variability of the disorder and in observing long-term outcome in the absence of targeted remediations. This study allows one to examine the first unselected cohort of patients and serves to highlight the importance of deletion testing in parents of affected probands.

METHODS

Thirty individuals with a 22q11.2 deletion were identified following the diagnosis in a relative. Nineteen were adults ascertained only following the diagnosis in their child, 10 were children identified following the diagnosis in their sibling, and one was a child diagnosed prenatally following the diagnosis in her parent.

RESULTS

Sixty percent of patients had no visceral anomalies. In fact, only 6 of the 19 adults (32%) and 6 of the 11 children (55%) had major findings which would have brought them to medical attention. Deletion sizing demonstrated the same large 3-4 MB deletion in most families despite wide inter and intrafamilial variability and there was no difference in clinical findings based on the parent of origin. Thus, no genotype-phenotype correlations could be made.

CONCLUSION

We report the first unselected cohort of patients with the 22q11.2 deletion identified through an affected relative. Analysis of this series of 30 patients, many with very mild manifestations of the deletion, allows one to examine the outcome in individuals who lacked specific remediations for this disorder. It emphasizes the importance of broadening the index of suspicion in order to provide appropriate recurrence risk counseling, cognitive remediation, and medical management. Further, it underscores the lack of familial concordance and the current lack of genotype-phenotype correlations in this disorder, and it raises the possibility that the deletion is more common than previously reported.

Psychoeducational profile of the 22q11.2 microdeletion: A complex pattern

OBJECTIVES

To examine the psychoeducational profile associated with the chromosome 22q11.2 microdeletion (DiGeorge/velocardiofacial syndrome).

STUDY DESIGN

Thirty-three patients (aged 6 to 27 years) with a 22q11.2 microdeletion underwent psychoeducational testing as part of a comprehensive evaluation. Nonparametric statistics were used to compare verbal and performance IQ, academic achievement scores, and receptive versus expressive language scores. Post hoc comparisons were made of IQ subtest scores and of language versus verbal IQ.

RESULTS

Full-scale IQ ranged from the normal to the moderately retarded range. Mean verbal IQ was significantly higher than mean performance IQ. In a similar manner, mean reading and spelling scores were superior to the mean mathematics score, although achievement scores typically were in the range of verbal IQ. In addition, many children showed clinically significant language impairments, with mean language scores lower than mean verbal IQ.

CONCLUSIONS

The IQ and academic profiles are reminiscent of a "nonverbal learning disability," although achievement was not discrepant from IQ. The coincidence of language impairment with a relative strength in reading belies a unique neuropsychologic profile. Educational programming for these children must address both verbal and nonverbal deficits.

Association of chromosome 22q11 deletion with isolated anomalies of aortic arch laterality and branching

OBJECTIVES

The purpose of this study was to determine the frequency of chromosome 22q11 deletions in patients with isolated anomalies of the aortic arch and its branches.

BACKGROUND

Chromosome 22q11 deletions are often present in patients with certain forms of congenital cardiovascular disease, including tetralogy of Fallot, truncus arteriosus and interruption of the aortic arch. Among patients with these anomalies, chromosome 22q11 deletion is more common in those with abnormal aortic arch laterality or branching.

METHODS

We studied 66 patients with isolated anomalies of the aortic arch and no associated intracardiac defects for deletions within chromosome 22q11, using fluorescence in situ hybridization with the cosmid probe N25 (D22S75). Arch anomalies included: double aortic arch (n = 22); right aortic arch with aberrant left subclavian artery (n = 28); right aortic arch with mirror-image branching and a vascular ring formed by a left-sided ductus from the descending aorta (n = 5); right aortic arch with mirror-image branching and no vascular ring (n = 4); and left aortic arch with aberrant right subclavian artery (n = 7). In addition, four patients had a cervical aortic arch, four had aortic coarctation and six had hypoplasia/atresia of the proximal pulmonary arteries.

RESULTS

Chromosome 22q11 deletions were found in 16 patients (24%) across the full spectrum of anomalies studied. Among the morphologic variables analyzed, only hypoplasia/atresia of the proximal pulmonary arteries correlated with the deletion (p = 0.03). Among patients with a double arch, the frequency of chromosome 22q11 deletion was higher in those with an atretic minor arch than it was in those with a patent minor arch (p = 0.02).

CONCLUSIONS

Chromosome 22q11 deletion is associated with isolated anomalies of laterality or branching of the aortic arch in 24% of cases in our series. These findings should alert the clinician to consider deletion screening in patients with isolated anomalies of the aortic arch.

Microdeletions of chromosomal region 22q11 in patients with congenital conotruncal cardiac defects

Congenital conotruncal cardiac defects occur with increased frequency in patients with DiGeorge syndrome (DGS). Previous studies have shown that the majority of patients with DGS or velocardiofacial syndrome (VCFS) have a microdeletion within chromosomal region 22q11. We hypothesised that patients with conotruncal defects who were not diagnosed with DGS or VCFS would also have 22q11 deletions. Seventeen non-syndromic patients with one of three types of conotruncal defects most commonly seen in DGS or VCFS were evaluated for a 22q11 deletion. DNA probes from within the DiGeorge critical region were used. Heterozygosity at a locus was assessed using restriction fragment length polymorphisms. Copy number was determined by dosage analysis using Southern blot analysis of fluorescence in situ hybridisation of metaphase spreads. Five of 17 patients were shown to have a 22q11 deletion when evaluated by dosage analysis. This study shows a genetic contribution to the development of some conotruncal cardiac malformations and alters knowledge regarding the risk of heritability of these defects in certain cases.

Anaplastic carcinoma of the thyroid: a 24-year experience

BACKGROUND

Anaplastic carcinoma of the thyroid gland is a lethal entity; few patients live more than 12 months following diagnosis. We retrospectively reviewed the experience with this entity at our cancer institute and identified a subgroup of patients with complete resection who have a 60% 5-year survival.

METHODS

Twenty-one cases of anaplastic carcinoma of the thyroid gland were analyzed retrospectively with respect to prognostic factors influencing survival. This represents 2.7% of 771 cases of thyroid cancer seen at our institution from 1968 to 1992. The median age at presentation was 65.1 years; male/female ratio was 1:1.1; and the most common symptom was a rapidly enlarging neck mass (76%).

RESULTS

Estimated 5-year survival was 10% (median: 4.5 months). Tumor size less than 6.0 cm (p = .004) and female gender (p = .02) were significant prognostic factors. Five patients who underwent complete resection had an estimated 5-year survival of 60% (median: 131 months). Four of these patients had postoperative radiotherapy with or without sequential chemotherapy. Two of these patients survived more than 10 years, and a third remains alive without disease at 26 months.

Preliminary phenotypic map of chromosome 4p16 based on 4p deletions

We have collected and analyzed clinical information from 11 patients with chromosome 4p deletions or rearrangements characterized by various molecular techniques. Comparing the extent of these patients' deletions with their respective clinical presentations led to the proposal of a preliminary phenotypic map of chromosome 4p. This map consists of regions which, when deleted, are associated with specific clinical manifestations. Nonspecific changes such as mental and growth retardation are not localized, and probably result from the deletion of more than one gene or region. The region associated with most of the facial traits considered typical in Wolf-Hirschhorn syndrome (WHS) patients coincides with the currently proposed WHS critical region (WHSCR), but some anomalies commonly seen in WHS appear to map outside of the WHSCR. The observation of clinodactyly in 2 patients with nonoverlapping deletions allows assignment of these defects to at least 2 separate regions in 4p16. These initial observations and attempts at genotype/phenotype correlation lay the groundwork for identifying the genetic basis of these malformations, a common objective of gene mapping efforts and chromosome deletion studies.

Cloning a balanced translocation associated with DiGeorge syndrome and identification of a disrupted candidate gene

DiGeorge syndrome (DGS), a developmental defect, is characterized by cardiac defects and aplasia or hypoplasia of the thymus and parathyroid glands. DGS has been associated with visible chromosomal abnormalities and microdeletions of 22q11, but only one balanced translocation--ADU/VDU t(2;22)(q14;q11.21). We now report the cloning of this translocation, the identification of a gene disrupted by the rearrangement and the analysis of other transcripts in its vicinity. Transcripts were identified by direct screening of cDNA libraries, exon amplification, cDNA selection and genomic sequence analysis using GRAIL. Disruption of a gene in 22q11.2 by the breakpoint and haploinsufficiency of this locus in deleted DGS patients make it a strong candidate for the major features associated with this disorder.

Pulmonary complications in patients undergoing thoracotomy for lung carcinoma

One hundred three consecutive patients undergoing 106 thoracotomies for primary lung carcinoma were reviewed to determine factors associated with the development of postoperative pulmonary complications. Pulmonary complications occurred in 40 of 104 (39 percent) patients. Minor complications occurred in 17 of 104 (16 percent) patients and major in 23 of 104 (22 percent). There were six deaths in the entire series of 103 patients (6 percent), two of which were directly caused by a pulmonary complication and one where it was a contributing factor. Extended surgical resections were associated with an increased risk of complications. Pulmonary complications occurred in 9 of 11 (82 percent) patients undergoing extended resections involving chest wall resection. The use of neoadjuvant chemotherapy also was associated with an increase in the rate of major complications. Poor nutritional status as measured by a history of weight loss and preoperative serum albumin levels also was associated with an increased risk of any pulmonary complication. Cardiac complications were significantly increased in the group of patients having pulmonary complications. Pulmonary complications continue to present a major source of morbidity and mortality for patients undergoing thoracotomy for lung carcinoma. Determination of factors associated with increased risk is important in order to identify patients who might be predisposed to the development of these complications.

The 22q11.2 deletion: screening, diagnostic workup, and outcome of results; report on 181 patients

A submicroscopic deletion of chromosome 22q11.2 has been identified in the majority of patients with the DiGeorge syndrome, velocardiofacial syndrome, conotruncal anomaly face syndrome, and in some patients with isolated conotruncal cardiac anomalies, Opitz G/BBB syndrome, and Cayler cardiofacial syndrome. We have evaluated 181 patients with this deletion. We describe our cohort of patients, how they presented, and what has been learned by having the same subspecialists evaluate all of the children. The results help define the extremely variable phenotype associated with this submicroscopic deletion and will assist clinicians in formulating a management plan based on these findings.

Hydrogen peroxide is involved in hamster sperm capacitation in vitro

We have investigated the possibility that the generation of hydrogen peroxide (H2O2) by spermatozoa plays a physiological role during capacitation. Capacitation is defined as the incubation period required for fertilization in mammals. Capacitation culminates in an exocytotic event, the acrosome reaction (AR). Mammalian sperm generate H2O2 during aerobic incubation and do not contain catalase, the enzyme that promotes scavenging of H2O2. In the present work we show that added catalase inhibited the AR, while glucose oxidase (GO), an enzyme that generates H2O2, accelerated the onset of the AR. Direct addition of H2O2 also stimulated the AR; catalase inhibited both the stimulation by GO and by H2O2. The onset of the AR was always preceded by the appearance of hyperactivated motility. The stimulation of the AR by H2O2 was manifest 1-2 h after the addition of H2O2. Catalase added at 3 h of incubation was less effective in inhibiting the AR than catalase added at the beginning. Incubation of sperm with catalase prevented the induction of the AR by the membrane-perturbing lipid, lysophosphatidyl choline. Taken together, these results suggest that H2O2 produced by hamster sperm plays a significant role during capacitation, possibly in membrane reorganization to facilitate the fusion that takes place during exocytosis of the acrosomal contents.

Identification of a mutation in a GATA binding site of the platelet glycoprotein Ibbeta promoter resulting in the Bernard-Soulier syndrome

Bernard-Soulier Syndrome (BSS) is a rare congenital bleeding disorder due to absent or decreased expression of the glycoprotein Ib-IX-V (GpIb-IX-V) receptor complex on the platelet surface. To date, only mutations in GpIbalpha or GpIX have been reported in patients with BSS. GpIbbeta differs from the other proteins in this receptor in that the gene is more complex, and an alternative form is expressed in cells of non-megakaryocytic lineage, including endothelial cells. It appears that the megakaryocytic and endothelial cell mRNA species are transcribed from different start sites and have different proximal promoter regions. We have identified a patient with BSS who has a deletion on one chromosome 22, resulting in velocardiofacial syndrome. The GpIbbeta gene has been mapped to this deleted (22q11.2) region of chromosome 22. The patient has greatly reduced levels of GpIbbeta mRNA and no detectable platelet GpIbbeta protein, suggesting that his BSS results from a mutation in his remaining GpIbbeta allele. Sequence analysis revealed that the coding region of GpIbbeta is normal, but the 5'-upstream region contains a C to G transversion at base -133 from the transcription start site used in megakaryocytes. The mutation changes a GATA consensus binding site, disrupts GATA-1 binding to the mutated site, and decreases promoter activity by 84%. Thus, in this patient, Bernard-Soulier syndrome results from a deletion of one copy of GpIbbeta and a mutated GATA binding site in the promoter of the remaining allele, resulting in decreased promoter function and GpIbbeta gene transcription.

Autosomal dominant "Opitz" GBBB syndrome due to a 22q11.2 deletion

We report on a family with autosomal dominant paternally inherited "Opitz" GBBB syndrome and an additional case with findings which have been reported in that syndrome. In each case the propositus presented with a vascular ring. Since a vascular ring may be a sign of a 22q11.2 deletion [Zacki et al., 1995], FISH (fluorescence in situ hybridization) studies were performed. These studies demonstrated a 22q11.2 deletion in the 3 affected individuals. Review of Opitz GBBB syndrome and the 22q11.2 microdeletion syndrome demonstrates significant overlap of manifestations including both facial characteristics and structural anomalies. Based on the phenotypic overlap and the presence of a 22q11.2 deletion in our patients with Opitz GBBB syndrome and the presence of a deletion in a patient with lung hypoplasia, absent pulmonary artery, and long segment tracheomalacia, we propose that, in some cases, the Opitz GBBB syndrome may be due to a 22q11.2 deletion. This enlarges the list of "syndromes" associated with the 22q11.2 deletion, which presently includes most patients with DiGeorge, velocardiofacial, and conotruncal anomaly face syndrome.