Spontaneous Pneumomediastinum: A Rare Disease Associated with Chest Pain in Adolescents

PURPOSE

Spontaneous pneumomediastinum (SPM) is a rare entity, with only a few cases reported, especially in adolescents. We aimed to analyze the clinical characteristics of SPM in adolescents and the diagnostic implications of computed tomography (CT) and esophagography therein.

MATERIALS AND METHODS

This retrospective descriptive study was conducted as a review of medical records of 416 adolescents (10-18 years of age) with chest pain from March 2005 to June 2013. Information on clinical presentation, methods of diagnosis, hospital stay, and outcomes were collected and analyzed.

RESULTS

Among adolescents complaining of chest pain, 11 patients had SPM (11/416, 2.64%). All patients presented with pleuritic chest pain, and 54.5% reported neck pain as the most common associated complaint. Clinical findings were nonspecific, and initial chest X-ray assessment was diagnostic only in three of 11 patients. However, reassessment of chest X-ray revealed diagnostic findings of SPM in five of the remaining eight patients. CT was diagnostic in all patients, while esophagography and echocardiogram were uninformative. Symptomatic improvement was noted within 2.45±1.2 hours (range, 0.5 to 4) after supportive care; mean hospital stay was 4.54±0.99 days (range, 2 to 6). No recurrence was observed.

CONCLUSION

SPM is a rare disease that should be considered in adolescent patients with pleuritic chest pain. Careful reading of initial chest X-rays is important to avoiding further unnecessary investigations. SPM is self-limited and treatment is supportive; nevertheless, if there are no indications of esophageal rupture, urgent esophagography is not recommended.

Analysis of Cardiovascular Risk Factors in Adults with Congenital Heart Disease

Background and Objectives

The objective of this study was to analyze cardiovascular risk factors in adults with congenital heart disease (ACHD).

Subjects and Methods

The subjects for this study comprised 135 patients, aged 18 years and above, who visited the ACHD clinic at the Samsung Medical Center and 135 adults with a structurally normal heart who were randomly selected from the Center for Health Promotion during the same period. For the analysis, the ACHD group was further divided into an ACHD group that underwent correction by cardiac surgery and a cyanotic group.

Results

The mean (standard diviation) age (years) of patients in the surgically corrected group was 48.4 (10.9) years, while that of patients in the cyanotic group was 43.1 (9.0) years and that of patients in the control group was 47.1 (10.3) years (p=0.042). The adjusted odds ratios (ORs) for past smoking, hypertension, diabetes mellitus, hypercholesterolemia, obesity, and metabolic syndrome were significantly higher in the surgically corrected patients than in the controls. However, the ORs for all variables excluding past smoking were significantly lower in the cyanotic group compared with the control group. After adjustment for age, gender, smoking, alcohol use, and exercise, the ORs for metabolic syndrome were 0.46 (0.35-0.57, p<0.001) and 1.48 (1.14-1.92, p=0.003) in the cyanotic and surgically corrected groups, respectively.

Conclusion

Cardiovascular risk factors need to be considered in surgically corrected ACHD patients as well as in adults with a structurally normal heart. A further study with a long-term follow-up is needed for developing guidelines for prevention.

A rare type of single coronary artery with right coronary artery originating from the left circumflex artery in a child

The presence of a single coronary artery is a rare congenital anomaly; such patients often present with severe myocardial ischemia. We experienced the case of a 13-year-old girl with the right coronary artery originating from the left circumflex artery. She visited our Emergency Department owing to severe chest pain; her cardiac enzyme levels were elevated, but her initial electrocardiogram (ECG) was normal. Echocardiography showed normal anatomy and normal regional wall motion. When she presented with recurrent chest pain on admission, the ECG showed significant ST-segment elevation in the left precordial leads and inferior leads with ST-segment depression in aVR lead, suggesting myocardial ischemia, and her cardiac enzyme levels were also elevated. We performed coronary angiography that showed a single right coronary artery originating from the left circumflex artery without stenosis. We confirmed the presence of a single coronary artery using coronary computed tomography. In addition, the treadmill test that was performed showed normal results. She was discharged from the hospital without any medications but with a recommendation of a regular follow-up.

Totally thoracoscopic ablation for treatment of atrial fibrillation after atrial septal defect device closure

Atrial septal defect (ASD) is one of the most common congenital heart defects in adults. Surgical repair is the most common treatment approach, but device closure has recently become widely performed in accordance with the trend toward less invasive surgical approaches. Although surgery is recommended when ASD is accompanied by atrial fibrillation, this study reports a case in which a complete cure was achieved by closure of a device and totally thoracoscopic ablation.

A pediatric case of Brugada syndrome diagnosed by fever-provoked ventricular tachycardia

Brugada syndrome is a rare channelopathy associated with the SCN5A gene that causes fatal ventricular arrhythmias. This case of Brugada syndrome, in which ventricular tachycardia (VT) was provoked by high fever, is the first report in a Korean child. The boy had retinoblastoma of his left eye diagnosed at 16 months of age. After chemotherapy, he contracted a catheter-related infection with a high fever up to 41℃ leading to monomorphic VT. This was characterized as having right bundle branch block morphology, superior axis deviation, and a heart rate of 212/min. Direct current cardioversion recovered the VT to sinus rhythm after a lack of response to amiodarone and lidocaine. A second attack of VT that was not controlled by cardioversion, however, responded to lidocaine. The baseline electrocardiogram showed a long PR interval and QRS duration, and the patient's grandfather had a history of Brugada syndrome. A mutation in SCN5A was identified in this patient, his father, and his grandfather. The patient was treated with quinidine and followed up for 1 year.

The evaluation of combined chemical and physical treatments on the reduction of resident microorganisms and Salmonella Typhimurium attached to chicken skin

This study was conducted to evaluate the efficacy of sodium hypochlorite (NaOCl, 0-200 mg/kg), thiamine dilauryl sulfate (TDS, 1,000 mg/kg), and ultrasound (37 kHz, 380 W) on reducing Salmonella Typhimurim, mesophilic aerobic bacteria (MAB), and coliforms on chicken skin. Chemical and physical treatments were applied for 5 min either singly or jointly, and Salmonella previously inoculated on chicken skin were quantitatively assessed using brilliant green agar, and the populations of MAB and coliforms in the native flora were enumerated using plate count agar and violet red bile agar, respectively. In the evaluation of bacterial attachment/detachment, chicken skin was quantitatively assessed for loosely, intermediately, and tightly attached bacteria. The treatment effects on bacteria detachment were also visualized using field emission scanning electron microscopy. In addition, color and textural properties of the skin after treatments were evaluated using a color difference meter and texture analyzer. Antimicrobial activity of NaOCl increased as the NaOCl concentration was increased, especially for loosely attached cells. The combination of 200 mg/kg NaOCl and ultrasound (NaOCl/ultrasound) significant reduced loosely, intermediately, and tightly attached bacteria populations by 0.75 to 0.47, 0.43 to 0.41, and 0.83 to 0.54 log cfu/g for MAB, coliforms, and Salmonella Typhimurium, respectively. However, the combination of NaOCl and TDS (NaOCl/TDS) did not sufficiently reduce those cells on chicken skins, except for loosely attached MAB and coliforms. The NaOCl/ultrasound combination produced a higher reduction in numbers of inoculated and native bacteria flora than any single application, with no negative effect on skin color or texture. Generally, the loosely attached bacteria were less resistant to the chemical and physical treatments than the intermediately and tightly attached bacteria in chicken skin, presumably due to their location in deeper skin layer and crevices. Further research is needed to investigate how the intermediately and tightly attached microorganisms can be effectively eliminated from chicken skin.

Surgery for partial anomalous pulmonary venous connections: modification of the warden procedure with a right atrial appendage flap

Background

Surgical repair of a partial anomalous pulmonary venous connection (PAPVC) to the superior vena cava (SVC) may be complicated by sinus node dysfunction or SVC obstruction. We modified the Warden procedure by using a right atrial auricular flap to decrease the occurrence of these complications.

Methods

Between February 2005 and July 2012, 10 consecutive patients underwent a modified Warden procedure to correct PAPVC. The median patient age was 5.7 years. Eight patients (80%) had an atrial septal defect. To surgically correct the PAPVC, we made a U-shaped incision on the right atrial appendage and sutured the flap to the posterior wall of the SVC. The anterior wall was reconstructed with various patch materials.

Results

No early or late deaths occurred, nor did any patient require early or late reoperation for SVC or pulmonary venous obstruction. No new arrhythmias appeared during follow-up, which was complete in all patients (mean, 29.5 months).

Conclusion

Our modification of the Warden procedure seems to be effective and safe. This technique may lower the risk of SVC obstruction, pulmonary venous obstruction, and sinus dysfunction.

Changes in coronary perfusion after occlusion of coronary arteries in Kawasaki disease

PURPOSE

Myocardial infarction in children with total occlusion of a coronary artery after Kawasaki disease is rare due to multiple collateral vessels. We aimed to investigate the changes in coronary perfusion associated with coronary artery occlusion after Kawasaki disease.

MATERIALS AND METHODS

Eleven patients with coronary artery occlusion after Kawasaki disease were investigated. Serial coronary angiographies after total occlusion of a coronary artery were reviewed and the changes were described in all patients with additive information collected.

RESULTS

The median age at the occlusion was 5.9 years old. The interval to occlusion was 6.2±6.9 years. Four left anterior descending coronary artery total occlusions and 10 right coronary artery total occlusions were detected. Immediate coronary artery bypass graft for left anterior descending coronary artery total occlusion made right coronary total occlusion occurred in all except one patient and the intervals thereof were 1 year, 1.8 years, and 4 years. Collaterals to the left coronary artery regressed after recanalization, while new collaterals to the right coronary artery developed. In three, collaterals to the right coronary artery decreased without recanalization without clinical signs.

CONCLUSION

The right coronary artery should be followed up carefully because of possible occlusion of new onset or changes in collaterals.

Application of the defect area in transcatheter closure of atrial septal defect

OBJECTIVES

It was our aim to evaluate whether the defect area plays a crucial role in successful device closure of atrial septal defects (ASDs).

METHODS

The long and short diameters of the defect were measured on en-face images. The defect area was then measured by planimetry. The device size compared to the defect length and defect area was analyzed in each group.

RESULTS

There were 22 patients in the circular group and 45 patients in the noncircular group. The defect area did not differ between the groups (201.6 ± 107.1 vs. 245.6 ± 127.6 mm(2)). Although the length between the device size and the long diameter differed between the groups (3.4 ± 2.0 vs. 0.8 ± 3.7 mm; p = 0.003), there was no difference in the ratio of the device area compared to the defect area, which was constant even in the noncircular defect (1.73 ± 0.41 vs. 1.72 ± 0.53 mm(2); p = 0.947). The device size was positively correlated with the defect area (p < 0.01).

CONCLUSION

The defect area measured by planimetry on en-face images might be useful in selecting the device size for transcatheter closure of ASDs.

Transcatheter closure of small ductus arteriosus with amplatzer vascular plug

PURPOSE

The purpose of this study was to share our experience of transcatheter closure of small patent ductus arteriosus (PDA) by using an Amplatzer vascular plug (AVP).

METHODS

We reviewed the medical records of 20 patients who underwent transcatheter closure at Samsung Medical Center and Sejong General Hospital from January 2008 to August 2012. The size and shape of the PDAs were evaluated by performing angiograms, and the PDA size and the AVP devices size were compared.

RESULTS

The mean age of the patients was 54.9±45.7 months old. The PDAs were of type C (n=5), type D (n=12), and type E (n=3). The mean pulmonary end diameter of the PDA was 1.7±0.6 mm, and the aortic end diameter was 3.6±1.4 mm. The mean length was 7.3±1.8 mm. We used 3 types of AVP devices: AVP I (n=5), AVP II (n=7), and AVP IV (n=8). The ratio of AVP size to the pulmonary end diameter was 3.37±1.64, and AVP size/aortic end ratio was 1.72±0.97. The aortic end diameter was significantly larger in those cases repaired with AVP II than in the others (P=0.002). The AVP size did not significantly correlate with the PDA size, but did correlate with smaller ratio of AVP size to aortic end diameter (1.10±0.31, P=0.032).

CONCLUSION

Transcatheter closure of small PDA with AVP devices yielded satisfactory outcome. AVP II was equally effective with smaller size of device, compared to others.

Fragmented QRS complex in adult patients with Ebstein anomaly and its association with arrhythmic risk and the severity of the anomaly

BACKGROUND

Fragmented QRS complex (fQRS) on 12-lead ECG, a marker of myocardial scar, is a predictor of arrhythmic events in patients with ischemic and nonischemic cardiomyopathy. We investigated whether the presence of fQRS is associated with the severity of the anomaly and with increased arrhythmic events in adult patients with Ebstein anomaly (EA).

METHODS AND RESULTS

In 51 consecutive adult patients with EA (median age, 37 years; 18 males), the severity index of EA calculated from echocardiographic data and clinical arrhythmic events were analyzed. The extent of fQRS in each patient was measured by counting the number of ECG leads showing fQRS. There were 35 (68.6%) patients with fQRS (fQRS group) and 16 (31.4%) patients without fQRS (non-fQRS group). fQRS was observed more frequently in the inferior (n=26) and precordial (n=25) leads versus the lateral leads (n=5). The patients in the fQRS group had a worse functional class, greater cardiothoracic ratios, more severe tricuspid regurgitation, larger atrialized right ventricular areas, higher EA severity scores, and more frequent arrhythmic events compared with those in the non-fQRS group. The atrialized right ventricular area showed a positive correlation with the fQRS extent (r=0.51; P<0.001). In multivariable Cox regression models, the presence of fQRS was independently associated with arrhythmic events (P=0.036).

CONCLUSIONS

Fragmented QRS on 12-lead ECG was associated with larger atrialized right ventricular area and an increased risk of arrhythmic events in adult patients with EA.

Balloon occlusive diameter of non-circular atrial septal defects in transcatheter closure with amplatzer septal occluder

Background and Objectives

The aim of this study was to investigate the balloon occlusive diameter (BOD) of non-circular defects in the transcatheter closure of atrial septal defect (ASD).

Subjects and Methods

A total of 67 patients who had undergone transcatheter closure of an ASD were reviewed retrospectively. A non-circular defect was defined as the ratio of the short diameter to the long diameter of the defect on the en-face image less than 0.75. The BOD was compared with the long diameter of the defect and then compared between the two groups.

Results

There were 22 patients with circular defects and 45 patients with non-circular defects. The difference in BOD measuring from the long diameter of the defect was quite different between the two groups and significantly smaller in non-circular morphology (0.1±4.0 vs. 2.3±2.1, p=0.006). The difference in BOD measurement from the long diameter of ASD showed a positive correlation with the ratio of the short diameter to the long diameter of ASD (b/a) (r²=0.102, p=0.008). In the non-circular morphology of ASD, the difference in BOD measured from the long diameter had a significant negative correlation with the long diameter of ASD (r²=0.230, p=0.001), whereas in circular ASD, no significant correlation was found between the difference in BOD and the long diameter of ASD (p=0.201).

Conclusion

The BOD compared with the long diameter measured from three-dimensional transesophageal echocardiography was smaller in non-circular ASD than in circular ASD. This difference was much smaller in non-circular ASD with a large long diameter.

The hybrid perventricular closure of apical muscular ventricular septal defect with Amplatzer duct occluder

PURPOSE

Apical muscular ventricular septal defects (MVSDs), especially in small infants, can be difficult to manage using surgical and percutaneous closure. An intraoperative perventricular procedure is a good option for closing apical MVSDs in small children with or without associated cardiac anomalies. We evaluated the results of hybrid perventricular closure of apical MVSDs performed using an Amplatzer duct occluder (ADO).

METHODS

We retrospectively reviewed the medical records of 5 patients who underwent hybrid perventricular closure of MVSDs with ADOs, from March 2006 to May 2011. The median patient age at the time of the procedure was 12 months (range, 25 days to 25 months), and the median body weight was 9.1 kg (range, 4.3 to 15 kg). Two patients had multiple ventricular septal defects (VSDs; additional perimembranous VSD in 1 patient and multiple MVSDs in the other) and 3 patients had associated cardiac anomalies; complete transposition of the great arteries in 1 patient and an atrial septal defect in 2 patients. All the procedures were performed on beating hearts, exception in 1 case. The ADO selected for the aortic side was at least 1 to 2 mm larger than the largest VSD in the left ventricle side.

RESULTS

The procedure was successful in all patients and each device was well positioned. During the median follow-up of 2.4 years, a small residual VSD was noted in 2 patients who had multiple VSDs and no leakage was seen in the other 3 patients.

CONCLUSION

Perventricular closure of MVSD with an ADO is a good option for patients with apical MVSD. However, careful manipulation is important, especially in the case of small infants.

Interstage mortality for functional single ventricle with heterotaxy syndrome: a retrospective study of the clinical experience of a single tertiary center

Background

In spite of improved survival after palliation for single ventricle, interstage mortality for a single ventricle with heterotaxy syndrome is unknown. The purpose of this study was to quantify interstage mortality and influence mortality risk factors.

Methods

From November 1994 until February 2012, all patients that had a functional single ventricle and heterotaxy syndrome who underwent palliative operations at our center were included. Patients with hypoplastic left heart syndrome and operative mortality cases were excluded. The factors that influenced interstage mortality were determined by multivariate Cox analysis.

Results

There were 16 patients with interstage mortality (41.0%), much higher than the non-heterotaxy group (vs. 11.3%, P = 0.001, OR = 5.478). The major presumptive causes of death were infection or sepsis (37.5%) and unknown sudden death (31.3%). When we compared the survival group and the mortality group with heterotaxy syndrome, Blalock-Taussig shunt as a 1st palliation is most common for both groups but there were more for the mortality group (81.2% vs. 52.2%), and there were more with bidirectional cavo-pulmonary shunt as a 1st palliation in the survival group (10 patients vs. 2 patients). The existence of pulmonary vein stenosis at initial diagnosis was more common for the mortality group. In multivariate Cox analysis, however, the duration of hospitalization at palliation, the duration of intensive care unit stay after palliation and the existence of pulmonary vein stenosis at diagnosis were significant risk factors.

Conclusion

Interstage mortality for a functional single ventricle with heterotaxy syndrome is significantly higher than for non-heterotaxy syndrome. Therefore more attention should be given to the prevention of interstage mortality in these patients with risk factors.

Amiodarone and catheter ablation as cardiac resynchronization therapy for children with dilated cardiomyopathy and wolff-Parkinson-white syndrome

Preexcitation by accessory pathways (APs) is known to cause dyssynchrony of the ventricle, related to ventricular dysfunction. Correction of ventricular dyssynchrony can improve heart failure in cases of dilated cardiomyopathy (DCMP) with preexcitation. Here, we report the first case of a child with DCMP and Wolff-Parkinson-White (WPW) syndrome treated with amiodarone and radiofrequency catheter ablation (RFCA) in Korea. A 7-year-old boy, who suffered from DCMP and WPW syndrome, showed improved left ventricular function and clinical functional class after treatment with amiodarone to eliminate preexcitation. QRS duration and left ventricular ejection fraction (LVEF) were inversely correlated with amiodarone dosage. After confirming the reduction of preexcitation effects in DCMP, successful RFCA of the right anterior AP resulted in LVEF improvement, along with the disappearance of preexcitation. Our findings suggest that ventricular dyssynchrony, caused by preexcitation in DCMP with WPW syndrome, can worsen ventricular function and amiodarone, as well as RFCA, which should be considered as a treatment option, even in young children.

Electric double layer at the interface of ionic liquid-dielectric liquid under electric field

The structure of the electric double layer (EDL) is analyzed in order to understand the electromechanical behavior of the interface of ionic liquid-dielectric liquid. The modified Poisson-Boltzmann equation proposed by Bazant et al. is solved to see the crowding and the overscreening effects that are the characteristics of an ionic liquid (Bazant, M. Z.; Storey, B. D.; Kornyshev, A. A. Double layer in ionic liquids: Overscreening versus crowding. Phys. Rev. Lett. 2011, 106, 046102.). From the simple one-dimensional (1-D) analysis, it is found that the changes of the composition and the material properties in the EDL are negligible except under some extreme conditions such as strong electric field over O(10(8)) V/m. From the electromechanical view points, an ionic liquid behaves like a pure conductor at the interface with a dielectric liquid. Based on these findings, three specific application problems are considered. In the first, a new method is suggested for measuring the interfacial tension of an ionic liquid-dielectric liquid system. The deformation of a charged ionic liquid droplet translating between two electrodes is used for this measurement. The second is for the Taylor cone problem, which includes an extreme electric field condition near the tip. The size of the critical region, where the EDL effect should be considered, is estimated by using the 1-D analysis result. Numerical computation is also performed to see the profiles of electric potential and the electric stress along the interface of the Taylor cone. Lastly, the electrowetting problem of the ionic liquid is considered. The discrepancies in the results of previous workers are interpreted by using the results of the present work. It is shown that all the results might be consistent if the leaking of the dielectric layer and/or the adsorption of ions is considered.

Surgical strategy in patients with atrial septal defect and severe pulmonary hypertension

The aim of the study was to review our experience with atrial septal defect (ASD) closure with a fenestrated patch in patients with severe pulmonary hypertension. Between July 2004 and February 2009, 16 patients with isolated ASD underwent closure with a fenestrated patch. All patients had a secundum type ASD and severe pulmonary hypertension. Patients ranged in age from 6 to 57 years (mean ± SD, 34.9 ± 13.5 years). The follow-up period was 9 to 59 months (mean, 34.5 ± 13.1 months). The ranges of preoperative systolic and pulmonary arterial pressures were 63 to 119 mm Hg (mean, 83.8 ± 13.9 mm Hg) and 37 to 77 mm Hg (mean, 51.1 ± 10.1 mm Hg). The ranges of preoperative values for the ratio of the pulmonary flow to the systemic flow and for pulmonary arterial resistance were 1.1 to 2.7 (mean, 1.95 ± 0.5) and 3.9 to 16.7 Wood units (mean, 9.8 ± 2.9 Wood units), respectively. There was no early or late mortality. Tricuspid annuloplasty was performed in 14 patients (87.5%). The peak tricuspid regurgitation gradient and the ratio of the systolic pulmonary artery pressure to the systemic arterial pressure were decreased in all patients. The New York Heart Association class and the grade of tricuspid regurgitation were improved in 13 patients (81.2%) and 15 patients (93.7%), respectively. ASD closure in patients with severe pulmonary hypertension can be performed safely if we create fenestration. Tricuspid annuloplasty and a Cox maze procedure may improve the clinical result. Close observation and follow-up will be needed to validate the long-term benefits.

Relation of fragmented QRS complex to right ventricular fibrosis detected by late gadolinium enhancement cardiac magnetic resonance in adults with repaired tetralogy of fallot

Fragmented QRS (fQRS) on 12-lead electrocardiography reflects conduction delay caused by myocardial fibrosis and dysfunction. Ventricular fibrosis detected by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is reportedly correlated with worse clinical outcomes in adults with repaired tetralogy of Fallot (TOF). The aim of this study was to assess whether the presence of fQRS is associated with right ventricular (RV) fibrosis or dysfunction in this patient group. In 37 consecutive patients (median age 30 years, median age at repair 6.6 years), the number of leads showing fQRS, defined as the presence of >2 notches on the R/S wave in ≥2 contiguous leads, was counted. RV systolic function, dilatation, and LGE score were measured using LGE CMR. Ventricular LGE was observed mainly at the previous surgical sites: the RV outflow tract (33 of 37), ventricular septal defect patch region (15 of 37), and RV anterior wall (11 of 37). Fragmented QRS was found mostly in the right and mid precordial leads. The fQRS group (n = 20) demonstrated higher RV LGE scores (p <0.001) and lower RV ejection fractions (p = 0.02) and a trend toward larger RV end-diastolic and end-systolic volumes (p = 0.12 and p = 0.06, respectively) compared to the non-fQRS group (n = 17). The number of electrocardiographic leads showing fQRS was positively correlated with RV LGE score (r = 0.75, p <0.001). The presence of fQRS remained independently associated with the presence of supramedian RV LGE score, even after adjusting for relevant parameters. In conclusion, fQRS was closely associated with more extensive RV fibrosis and dysfunction in adults with repaired tetralogy of Fallot.

Multiple displacement amplification for preimplantation genetic diagnosis of fragile X syndrome

Preimplantation genetic diagnosis (PGD) has become an assisted reproductive technique for couples that have genetic risks. Despite the many advantages provided by PGD, there are several problems, including amplification failure, allele drop-out and amplification inefficiency. We evaluated multiple displacement amplification (MDA) for PGD of the fragile X syndrome. Whole genome amplification was performed using MDA. MDA products were subjected to fluorescent PCR of fragile X mental retardation-1 (FMR1) CGG repeats, amelogenin and two polymorphic markers. In the pre-clinical tests, the amplification rates of the FMR1 CGG repeat, DXS1215 and FRAXAC1 were 84.2, 87.5 and 75.0%, respectively, while the allele dropout rates were 31.3, 57.1 and 50.0%, respectively. In two PGD treatment cycles, 20 embryos among 30 embryos were successfully diagnosed as 10 normal embryos, four mutated embryos and six heterozygous carriers. Three healthy embryos were transferred to the uterus; however, no clinical pregnancy was achieved. Our data indicate that MDA and fluorescent PCR with four loci can be successfully applied to PGD for fragile X syndrome. Advanced methods for amplification of minuscule amounts of DNA could improve the sensitivity and reliability of PGD for complicated single gene disorders.