• Journal of Genetic Medicine
• /
• v.8 no.1
• /
• pp.44-52
• /
• 2011

Purpose: Cytogenetic analysis of spontaneous abortions (SABs) provides valuable information to establish the causes of fetal loss, information that is essential to provide accurate reproductive and genetic counseling couples. Such analysis also provides information on the frequencies and types of chromosomal abnormalities and associated risks of recurrence. However, there have only been a few reports of chromosomal abnormalities in small samples of SABs in the Korean population. Here, we report the incidence and spectrum of chromosomal abnormalities for cases of 470 SAB in Korea. Material and Methods: Between 2005 and 2010, a total of 470 products of conception (POC) resulting from SABs were submitted to our laboratory for cytogenetic analysis from various medical sites in Korea. The incidences and types of specific chromosomal abnormalities were determined. The abnormalities were distinguished by gestational age at the time of SAB and by maternal age. Results: The frequency of chromosomal abnormalities in POCs was 54.3% (255/470), including 228 (89.3%) numerical and 27 (10.7%: 3 balanced and 24 unbalanced) structural abnormalities. Among the numerical abnormalities, trisomy was predominant (67.0%), followed by monosomy X (12.5%), polyploidy (8.2%), triple X (0.8%), and autosomal monosomy (0.8%). The overall sex ratio (male: female) among the 470 POCs with normal and abnormal karyotypes were 0.58 and 0.65, respectively. Trisomies were identified for each autosome, with the exceptions of 1, 3, and 19. Among the 171 autosomal trisomies, trisomy 16 was the most common (19.9%), followed by trisomy 22 (13.5%), trisomy 21 (12.3 %), trisomy 15 (9.9%), and trisomies 18 and 13 (5.3%). The frequency of chromosomal abnormalities decreased with gestational age and increased with maternal age, but only because of increases in trisomies and complex abnormalities. Conclusions: We have presented a large collection of cytogenetic data for SABs collected during the past 6 years and provided a database for prenatal genetic counseling of parents who have experienced SABs in Korea.

• Journal of Genetic Medicine
• /
• v.12 no.2
• /
• pp.79-84
• /
• 2015

Purpose: We developed and validated a fetal trisomy detection method for use as a noninvasive prenatal test (NIPT) including a Clinical Laboratory Improvement Amendments (CLIA)-certified bioinformatics pipeline on a cloud-based computing system using both Illumina and Life Technology sequencing platforms for 221 Korean clinical samples. We determined the necessary proportions of the fetal fraction in the cell-free DNA (cfDNA) sample for NIPT of trisomies 13, 18, and 21 through a limit of quantification (LOQ) test. Materials and Methods: Next-generation sequencing libraries from 221 clinical samples and three positive controls were generated using Illumina and Life Technology chemistries. Sequencing results were uploaded to a cloud and mapped on the human reference genome (GRCh37/hg19) using bioinformatics tools. Based on Z-scores calculated by normalization of the mapped read counts, final aneuploidy reports were automatically generated for fetal aneuploidy determination. Results: We identified in total 29 aneuploid samples, and additional analytical methods performed to confirm the results showed that one of these was a false-positive. The LOQ test showed that the proportion of fetal fraction in the cfDNA sample would affect the interpretation of the aneuploidy results. Conclusion: Noninvasive chromosome examination (NICE), a CLIA-certified NIPT with a cloud-based bioinformatics platform, showed unambiguous success in fetus aneuploidy detection.

• Clinical and Experimental Pediatrics
• /
• v.52 no.5
• /
• pp.603-606
• /
• 2009

The Pierre Robin sequence (PRS) is the nonrandom association of micrognathia, cleft palate, and glossoptosis, leading to respiratory and feeding difficulties that appear neurogenic rather than mechanical in causation. Genetic determinants are thought to underlie this functional and morphological entity, based on the existence of Mendelian syndromes with PRS. Here, we demonstrate the association of PRS with trisomy 8p due to duplication of a segment as the karyotype 46,XX,dup(8)(p21.3p23.1) and confirm the additional materials as chromosome 8 via whole chromosome paint probes. Our observation supports the hypothesis regarding a genetic basis for nonsyndromic PRS, strengthens the possible genetic association with isolated cleft palate, and provides a candidate PRS locus in chromosomal region 8(p21.3p23.1).

• Clinical and Experimental Pediatrics
• /
• v.54 no.6
• /
• pp.267-271
• /
• 2011

Distal duplication, or trisomy 15q, is an extremely rare chromosomal disorder characterized by prenatal and postnatal overgrowth, mental retardation, and craniofacial malformations. Additional abnormalities typically include an unusually short neck, malformations of the fingers and toes, scoliosis and skeletal malformations, genital abnormalities, particularly in affected males, and, in some cases, cardiac defects. The range and severity of symptoms and physical findings may vary from case to case, depending upon the length and location of the duplicated portion of chromosome 15q. Most reported cases of duplication of the long arm of chromosome 15 frequently have more than one segmental imbalance resulting from unbalanced translocations involving chromosome 15 and deletions in another chromosome, as well as other structural chromosomal abnormalities. We report a female newborn with a de novo duplication, 15q24- q26.3, showing intrauterine overgrowth, a narrow asymmetric face with down-slanting palpebral fissures, a large, prominent nose, and micrognathia, arachnodactyly, camptodactyly, congenital heart disease, hydronephrosis, and hydroureter. Chromosomal analysis showed a 46,XX,inv(9)(p12q13),dup(15)(q24q26.3). Array comparative genomic hybridization analysis revealed a gain of 42 clones on 15q24-q26.3. This case represents the only reported patient with a de novo 15q24-q26.3 duplication that did not result from an unbalanced translocation and did not have a concomitant monosomic component in Korea.

• Clinical and Experimental Pediatrics
• /
• v.51 no.11
• /
• pp.1241-1244
• /
• 2008

We report on 2 siblings with a partial trisomy of 7q ($7q22{\rightarrow}qter$) and concomitant partial monosomy of 8p ($8p23.3{\rightarrow}pter$), which were shown by FISH using probes located at the telomere region of each chromosome. All the balanced translocation carriers (father and a sister) in this family had a normal phenotype. The 2 siblings with the same abnormal karyotype had similar multiple congenital anomalies and dysmorphic features. During the follow-up, the first male patient died in the neonatal period, but the female sibling is still alive at 2 years and 6 months of age.

• Journal of Chest Surgery
• /
• v.34 no.8
• /
• pp.626-629
• /
• 2001

Congenital polyvalvular disease is a connective tissue disorder affecting more than one heart valve with variable involvement of the entire valvular and subvalvular apparatus. It is frequently associated with the Trisomy 18 and trisomy 13-15 or ventricular septal defect and patent ductus arteriosus. We present an isolated case of congenital polyvalvular disease in a new born baby with a review of the pertinent literatures, which has not been described in Korea. The mass was discovered as a right atrial mass in the prenatal ultrasonography and it was thought to be either a hematoma or a myxoma in the preoperative echocardiography. Microscopic examination of the surgically resected mass showed irregular thickening, nodulation, and additional features of calcification and ossification in the valvular connective tissue on the body of anterior and septal leaflet of tricuspid valve. Congenital polyvalvular disease should be included in the differential diagnosis in cases showing valvular calcification or ossification in the fetal echocardiography.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.2
• /
• pp.199-210
• /
• 1997

A study has been carried out to elucidate the cytogenetic characteristics of Down's syndrome in Korea. This study includes 877 cases which were diagnosed as Down's syndrome by the chromosomal analyses at the Cytogenetic Laboratory, Institute of Reproductive Medicine and Population, Seoul National University for 13 years from January, 1984 to December, 1996. 1. 83.6% of cases were diagnosed under 1 year of age and 10.9% were between 1 and 4 years old. The overall sex ratio was 3 to 2 (male to female). 2. The most frequent indication for cytogenetic analyses was suspicion of Down's syndrome. The next were growth retardation, congenital heart diseases, congenital anomalies. 3. 88.4% of cases had free trisomy 21. In 6.5%, there was translocation, mostly Robertsonian t(14;21) or t(21;21). 3.9% of cases were mosaics mostly with one normal cell line. 4. Karyotyping was also performed in 204 parents of patients. 6 parents (2.9%) were seen to be translocation carriers of Down's syndrome. We find the unique features of Down's syndrome in Korea that the incidences of free trisomy 21 is relatively lower and that translocation is higher than western countries.

• Korean Journal of Bronchoesophagology
• /
• v.3 no.1
• /
• pp.128-136
• /
• 1997

Laryngomalacia is the most common cause of stridor in infant. It is a relatively benign self-limiting condition, but in severe cases, it results in obstructive sleep apnea, cor pulmonale , gastroesophageal reflux, failre to thrive, pectus excavatum, respiratory failure and death. When the airway obstruction related to laryngomalacia becomes significant, surgical correction of the underlying laryngeal deformity is indicated. Numerous reports provide evidence to support the trimming supraglottic soft tissue by using either conventional instruments or the surgical laser for treatment of severe laryngomalacia. Recently, authors experienced a case of laryngomalacia with Trisomy 13 (Patau syndrome) which had three times respiratory arrest and was treated with laser aryepiglottoplasty. We report this case with review of the literatures.

• Journal of Genetic Medicine
• /
• v.5 no.2
• /
• pp.125-130
• /
• 2008

Propose: To analyze the indications and cytogenetic results of midtrimester amniocentesis. Material and Methods: This study reviewed 2,523 cases of midtrimester prenatal genetic amniocentesis performed at MizMedi Hospital between January 2000 and December 2007. Results: The most frequent indication for midtrimester amniocentesis was advanced maternal age (45.9%), followed by positive serum markers (29.9%). Chromosomal aberrations were diagnosed in 110 cases (4.4%), for which numerical aberration accounted for 38 cases (34.5%), structural aberration accounted for 65 cases (59.1%), and mosaicism accounted for 7 cases (6.4%). Among the autosomal aberrations, there were 20 cases of trisomy 21 and 8 cases of trisomy 18. With respect to structural aberrations, there were 14 cases of reciprocal translocation and 8 cases of robertsonian translocation. The frequencies of chromosomal aberrations according to the indication were highest in individuals with a family history of chromosome abnormality 14.0% (8/57) followed by previous congenital anomaly 5.9% (2/34). Conclusion: Midtrimester amniocentesis is an effective tool for prenatal diagnosis. Indications such as advanced maternal age, maternal serum markers, and ultrasound are important for predicting abnormal fetal karyotypes.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.12 no.2
• /
• pp.77-81
• /
• 2016

The Dandy-Walker syndrome is a relatively rare congenital malformation occurring about one in 25,000-35,000 pregnancies. It is characterized by hydrocephalus, cystic dilatation of the fourth ventricle, complete or partial absence of the cerebellar vermis, and other various extra-CNS malformations. We report a dental caries treatment of a 4-year old girl with Dandy-Walker syndrome and partial trisomy 9q. The patient visited Seoul National University Dental Hospital due to multiple caries. The cause of multiple caries is mainly presumed as patient's eating habit caused by her general condition. She was still using milk bottle because she was having difficulties swallowing solid food due to breathing problem while eating. The treatment was performed under general anesthesia considering patient's condition; delayed development, very poor cooperation and respiratory problem. The dental procedure was successfully conducted and there were no postoperative complications. In consideration of her eating habit and oral hygiene problem, regular check appointment was recommended.