• Journal of Genetic Medicine
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• v.12 no.1
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• pp.57-60
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• 2015

CHARGE syndrome (coloboma, heart defects, atresia choanae, retarded growth and development, genital hypoplasia, and ear abnormalities) is characterized by multiple malformations and is diagnosed using distinct consensus criteria. Mutations in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7) are the major cause of CHARGE syndrome. Clinical features of CHARGE syndrome considerably overlap those of 22q11.2 deletion syndrome. Of these features, immunodeficiency and hypocalcemia are frequently reported in patients with 22q11.2 deletion syndrome but are rarely reported in patients with CHARGE syndrome. In this report, we have described the case of a patient with typical phenotypes of 22q11.2 deletion syndrome but without the proven chromosome microdeletion. Mutation analysis of CHD7 identified a pathogenic mutation (c.2238+1G>A) in this patient. To our knowledge, this is the first case of CHARGE syndrome with immunodeficiency and hypocalcemia in Korea. Our observations suggest that mutation analysis of CHD7 should be performed for patients showing the typical phenotypes of 22q11.2 deletion syndrome but lacking the proven chromosome microdeletion.

• Journal of Genetic Medicine
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• v.12 no.1
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• pp.44-48
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• 2015

Townes-Brocks syndrome (TBS) is a rare genetic disorder characterized by the classic triad of congenital anomalies of the anus, thumbs, and ears, with variable expressivity. Additionally, renal malformations, cardiac anomalies, and endocrine and eye abnormalities can accompany TBS, although less frequently. TBS is inherited in an autosomal dominant fashion; however, about 50% of patients have a family history of TBS and the remaining 50% have de novo mutations. SALL1, located on chromosome 16q12.1, is the only causative gene of TBS. SALL1 acts as a transcription factor and may play an important role in inducing the anomalies during embryogenesis. Clinical features of TBS overlap with those of other multiple anomaly syndromes, such as VACTERL syndrome, Baller-Gerold syndrome, Goldenhar syndrome, cat eye syndrome, and Holt-Oram syndrome. Consequently, there are some difficulties in differential diagnosis based on clinical manifestations. Herein, we report a Korean family with two generations of TBS that was diagnosed based on physical examination findings and medical history. Although the same mutation in SALL1 was identified in both the mother and the son, they displayed different clinical manifestations, suggesting a phenotypic diversity of TBS.

• Preventive Nutrition and Food Science
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• v.19 no.4
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• pp.247-260
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• 2014

The impact of folate on health and disease, particularly pregnancy complications and congenital malformations, has been extensively studied. Mandatory folic acid fortification therefore has been implemented in multiple countries, resulting in a reduction in the occurrence of neural tube defects. However, emerging evidence suggests increased folate intake may also be associated with unexpected adverse effects. This literature review focuses on contemporary issues of concern, and possible underlying mechanisms as well as giving consideration the future direction of mandatory folic acid fortification. Folate fortification has been associated with the presence of unmetabolized folic acid (PteGlu) in blood, masking of vitamin $B_{12}$ deficiency, increased dosage for anti-cancer medication, photo-catalysis of PteGlu leading to potential genotoxicity, and a role in the pathoaetiology of colorectal cancer. Increased folate intake has also been associated with twin birth and insulin resistance in offspring, and altered epigenetic mechanisms of inheritance. Although limited data exists to elucidate potential mechanisms underlying these issues, elevated blood folate level due to the excess use of PteGlu without consideration of an individual's specific phenotypic traits (e.g. genetic background and undiagnosed disease) may be relevant. Additionally, the accumulation of unmetabolized PteGlu may lead to inhibition of dihydrofolate reductase and other enzymes. Concerns notwithstanding, folic acid fortification has achieved enormous advances in public health. It therefore seems prudent to target and carefully monitor high risk groups, and to conduct well focused further research to better understand and to minimize any risk of mandatory folic acid fortification.

• Journal of Genetic Medicine
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• v.11 no.2
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• pp.86-90
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• 2014

Smith-Lemli-Opitz syndrome (SLOS) is a rare autosomal recessive disorder caused by 7-dehydrocholesterol reductase deficiency. The characteristic clinical features are syndactyly of the second and third toes, facial dysmorphism, multiple malformations, and intellectual disability. Few cases of SLOS have been reported in Korea. We observed a male patient with SLOS who presented with typical facial features, undescended testes, microcephaly, bilateral syndactyly of the second and third toes, and cardiac defects, including patent ductus arteriosus and atrial septal defect. Mutation analysis of the DHCR7 gene identified compound heterozygous mutations of c.907G>A (p.Gly303Arg) and c.1055G>A (p.Arg352Gln). In a review of the literature, c.1054C>T (p.Arg352Trp) was the most common mutation reported in Far East Asian countries. This report describes the clinical features, biochemical data, molecular characteristics, and clinical outcome of a Korean patient with SLOS.

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

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.6 no.2
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• pp.94-98
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• 2010

Axenfeld-Rieger syndrome is a rare autosomal dominant disorder characterized by various ocular and extraocular malformations. The incidence of Axenfeld-Rieger syndrome has been estimated to be 1 per 200,000. The syndrome is characterized by short body stature, delayed bone age, and deficient or arrested development of neural crest cells involving the anterior chamber of the eyes, facial bones, teeth, periumbilical skin, and cardiovascular system. This is a case of a 6 year-old girl, who came to the department of the pediatric dentistry, Yonsei University Dental Hospital, for evaluation and treatment of multiple congenital missing permanent teeth. The patient presented typical dental, craniofacial, and systemic features of Axenfeld-Rieger syndrome, such as glaucoma, oval pupil, heterochromatic iris, umbilical hernia, and delayed bone age. On the panoramic view, 3 primary teeth were missing and 13 permanent tooth germs were absent. On the lateral cephalograph, underdevelopment of the maxilla and normal growth pattern of the mandible were confirmed. Periodic dental follow-up is planned for evaluation and interceptive treatment of her dental and craniofacial problems. Denture or removable space maintainer with a pontic is considered for esthetic and functional restoration. In addition, orthognathic surgery is also planned in future to prevent further midfacial skeletal deformation. Early diagnosis of Axenfeld-Rieger syndrome is very important to prevent exacerbation of complications, such as glaucoma and skeletal deformities.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.374-380
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• 2010

Treacher Collins syndrome(TCS) is a rare, incurable condition occurring in approximately 1 of 25,000 to 50,000 births. It may occur as a spontaneous mutation out of genetically normal parents or it may be manifested as an autosomal dominant pattern. TCS is characterized by facial deformities such as, underdevelopment of the maxilla, mandible and zygoma, malocclusion, bilateral deformities of auricles, antimongoloid slant of the palpebral fissures. The syndrome is often associated with cleft lip and palate, ear malformations and hearing loss, short stature, and anomalies of the heart and skeleton. Respiratory difficulty associated with air way obstruction may also be observed, and there is considerable difficulty in airway management during general anesthesia. It is necessary that dentists provide safe dental treatments and guidelines to TCS patients by providing adequate understanding about the characteristics of the syndrome and proper ways of managements. The purpose of this study is to report the dental and medical characteristics of the patient who visited the Department of Pediatric Dentistry, Yonsei University for multiple dental caries treatment and to review the literatures of TCS.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.3
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• pp.103-108
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• 2017

Kabuki syndrome is a rare congenital disorder that causes multiple birth defects and mental retardation. Mutation of the lysine methyltransferase 2D (KMT2D) gene is the primary cause of Kabuki syndrome. We report a 4-year-old Korean girl diagnosed with Kabuki syndrome based on distinctive facial features (eversion of the lower lateral eyelid, arched eyebrows, depressed nasal tip, prominent ears), skeletal anomalies, short stature, and molecular analysis, which revealed a novel frameshift mutation in the KMT2D gene. A 4-year-old patient had a past history of congenital cardiac malformations (coarctation of the aorta, ventricular septal defect, atrial septal defect, patent ductus arteriosus), subclinical hypothyroidism and dysmorphic features at birth including webbed neck, short fingers, high arched palate, micrognathia and horseshoe kidney. She showed unique facial features such as a long palpebral fissure, long eyelashes, arched eyebrows with sparseness of the lateral third, broad nasal root, anteverted ears, and small mouth. Her facial features suggested Kabuki syndrome, and genetic analysis discovered a novel heterozygous frameshift mutation (c.4379dup, p.Leu1461Thrfs*30) in exon 15 of the KMT2D gene. The diagnosis of our 4-year-old patient was made through thorough physical examination and history taking, and genetic testing. It is challenging to diagnose patients with Kabuki syndrome at birth, since the characteristic facial features are expressed gradually during growth. Clinical suspicion aroused by regular follow-ups may lead to earlier diagnosis and interventions.