This correction is being published to correct the authors' names.

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.
Asian Continental Ancestry Group ; Cryptorchidism ; Ductus Arteriosus, Patent ; Far East ; Heart Septal Defects, Atrial ; Humans ; Intellectual Disability ; Korea ; Male ; Microcephaly ; Smith-Lemli-Opitz Syndrome* ; Syndactyly ; Toes

Dural ectasia refers to the widening or ballooning of the dural sac surrounding the spinal cord. It can affect any plane of the spinal canal, but occurs primarily in the lumbosacral region. Dural ectasia is present in 63-92% patients who have Marfan syndrome, and is related to Ehlers-Danlos syndrome, neurofibromatosis type I, and ankylosing spondylitis. The most common symptoms are low back pain, headache, weakness, numbness above and below the affected limb, and occasional rectal and genital pain. However, in most patients, dural ectasia is usually asymptomatic. We report the case of a 5-year-old boy who presented with a severe headache who had been diagnosed with Marfan syndrome. During the evaluation, magnetic resonance imaging of the lumbar and sacral spine revealed dural ectasia. To our knowledge, this is the first report on Marfan syndrome with symptomatic dural ectasia in Korea. We concluded that dural ectasia should be suspected in patients diagnosed with Marfan syndrome who have a severe headache.
Child, Preschool ; Dilatation, Pathologic* ; Ehlers-Danlos Syndrome ; Extremities ; Headache ; Humans ; Hypesthesia ; Korea ; Low Back Pain ; Lumbosacral Region ; Magnetic Resonance Imaging ; Male ; Marfan Syndrome* ; Neurofibromatosis 1 ; Spinal Canal ; Spinal Cord ; Spine ; Spondylitis, Ankylosing

Mowat-Wilson syndrome is an extremely rare genetic disease that is characterized by intellectual disability, facial dysmorphism, Hirschsprung's disease, and other congenital anomalies. This disorder is caused by heterozygous mutations or deletions in the zinc finger E-box-binding homeobox-2 gene (ZEB2). Thus far, approximately 200 cases of Mowat-Wilson syndrome have been reported worldwide. In Korea, only one case with a 2q22 deletion, which also affects ZEB2, has been previously reported. Here, we describe a patient with Mowat-Wilson syndrome who presented with developmental delays, typical facial dysmorphism, and Hirschsprung's disease. Molecular analysis of ZEB2 identified a novel heterozygous mutation at c.190dup (p.S64Kfs*6). To our knowledge, this is the second report of a Korean patient with Mowat-Wilson syndrome that has been confirmed genetically.
Hirschsprung Disease* ; Humans ; Intellectual Disability ; Korea ; Zinc Fingers

Sotos syndrome (SS, OMIM 117550) is characterized by prenatal and postnatal overgrowth with multiple congenital anomalies. However, there have been few cases of growth retardation caused by renal failure from infancy. We report a case of dysplasia of the bilateral kidneys with renal failure and poor postnatal growth. A 2-month-old boy visited the emergency room owing to poor oral intake and abdominal distension. He was born at the gestational age of 38 weeks with a birth weight of 4,180 g. After birth, he had feeding difficulty and abdominal distension. Upon physical examination, his height and weight were in less than the 3rd percentile, while his head circumference was in the 50th percentile on the growth curve. He also showed a broad and protruding forehead and high hairline. Blood laboratory tests showed severe azotemia; emergent hemodialysis was needed. Abdominal ultrasonography revealed bilateral renal dysplasia with multiple cysts and diffuse bladder wall thickening. A posterior urethral valve was suggested based on vesicoureterography and abdominal magnetic resonance findings. Results of a colon study to rule out congenital megacolon did not reveal any specific findings. The conventional karyotype of the patient was 46, XY. Array comparative genomic hybridization study revealed a chromosome 5q35 microdeletion including the NSD1 gene, based on which SS was diagnosed. We describe a case of SS presenting with end stage renal disease due to posterior urethral valve. The typical somatic overgrowth of SS in the postnatal period was not observed due to chronic renal failure that started in the neonatal period.
Azotemia ; Birth Weight ; Colon ; Comparative Genomic Hybridization ; Databases, Genetic ; Emergency Service, Hospital ; Forehead ; Gestational Age ; Head ; Hirschsprung Disease ; Humans ; Infant ; Karyotype ; Kidney ; Kidney Failure, Chronic* ; Male ; Parturition ; Physical Examination ; Renal Dialysis ; Renal Insufficiency ; Sotos Syndrome* ; Ultrasonography ; Urinary Bladder

PURPOSE: Spinocerebellar ataxia (SCA) is a genetically heterogeneous disease for which more than 30 subtypes have been identified. However, 5 subtypes, SCA1, SCA2, SCA3, SCA6, and SCA7, account for more than 60% of cases. In this study, we report the distribution of these 5 subtypes in Korean patients. MATERIALS AND METHODS: Six hundred and thirty-eight unrelated patients with a presumptive diagnosis of SCA were included in this study. Trinucleotide (CAG) repeat number (TNR) repeat number was determined using fluorescently labeled primers and fragment analysis. RESULTS: A total of 128 unrelated patients (20.1% of all individuals tested) tested positive for SCA subtypes, including SCA1 (5 patients, 3.9% of those testing positive), SCA2 (38 patients, 29.7%), SCA3 (30 patients, 23.4%), SCA6 (39 patients, 30.5%), and SCA7 (16 patients, 12.5%). The mean copy number of pathogenic TNR alleles was 45+/-8.5 for SCA1, 42+/-3.1 for SCA2, 72+/-5.4 for SCA3, 23+/-1.5 for SCA6, and 50+/-11.4 for SCA7. TNR copy number was inversely correlated with onset age in SCA2, SCA6, and SCA7. CONCLUSION: SCA2, SCA3, and SCA6 are common SCA subtypes in Korean patients and could be screened as a first-line test. Expanded pathogenic allele size was associated with early onset age.
Age of Onset ; Alleles ; Diagnosis ; Humans ; Spinocerebellar Ataxias* ; Trinucleotide Repeats

PURPOSE: The mutation of the SLC26A4 gene is the second most common cause of congenital hearing loss after GJB2 mutations. It has been identified as a major cause of autosomal recessive nonsyndromic hearing loss associated with enlarged vestibular aqueduct and Pendred syndrome. Although most studies of SLC26A4 mutations have dealt with hearing-impaired patients, there are a few reports on the frequency of these mutations in the general population. The purpose of this study was to evaluate the prevalence of SLC26A4 mutations that cause inherited deafness in the general Korean population. MATERIALS AND METHODS: We obtained blood samples from 144 Korean individuals with normal hearing. The samples were subjected to polymerase chain reaction to amplify the entire coding region of the SLC26A4 gene, followed by direct DNA sequencing. RESULTS: Sequencing analysis of this gene identified 5 different variants (c.147C>G, c.225G>C, c.1723A>G, c.2168A>G, and c.2283A>G). The pathogenic mutation c.2168A>G (p.H723R) was identified in 1.39% (2/144) of the subjects with normal hearing. CONCLUSION: These data provide information about carrier frequency for SLC26A4 mutation-associated hearing loss and have important implications for genetic diagnostic testing for inherited deafness in the Korean population.
Clinical Coding ; Deafness* ; Diagnostic Tests, Routine ; Hearing ; Hearing Loss ; Humans ; Polymerase Chain Reaction ; Prevalence ; Sequence Analysis, DNA ; Vestibular Aqueduct

PURPOSE: To assess the outcomes of increased fetal nuchal translucency (NT), to aid in prenatal counseling and management in our practice. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients who underwent first trimester fetal karyotyping using chorionic villi sampling (CVS) and second trimester level II sonography for a fetal NT thickness > or =3.0 mm between 11 weeks and 13 weeks 6 days' gestation, at Gyeongsang National University Hospital. Pediatric medical records and a telephone interview were used to follow-up live-born children. Exclusion criteria included incomplete data and CVS for other indications. RESULTS: Seventy cases met the inclusion criteria (median NT thickness, 4.7 mm; range, 3.0-16.1 mm). Twenty-nine cases (41.4%) were aneuploid. The prevalence of chromosomal defects increased with NT thickness: NT 3.0-3.4 mm, 16.7%; NT 3.5-4.4 mm, 27.3%; NT 4.5-5.4 mm, 66.7%; NT 5.5-6.4 mm, 37.5%; NT > or =6.5 mm, 62.5%. The most common karyotype abnormality was trisomy 18 (n=12), followed by trisomy 21 (n=9). In chromosomally normal fetuses (n=41), fetal death occurred in 2 cases (4.9%), and structural malformations were found in 11 cases (26.8%). In chromosomally and anatomically normal fetuses (n=28), one child had neurodevelopmental delay (3.6%). Twenty-eight infants who had a prenatal increased NT were alive and well at follow-up (40%). CONCLUSION: Outcomes of increased fetal NT might help inform prenatal counseling and management. The high prevalence of chromosomal defects associated with increased fetal NT implies that CVS should be performed in the first trimester, particularly considering the stress associated with an uncertain diagnosis.
Aneuploidy ; Child ; Chorionic Villi Sampling* ; Counseling ; Diagnosis ; Down Syndrome ; Female ; Fetal Death ; Fetus ; Follow-Up Studies ; Humans ; Infant ; Interviews as Topic ; Karyotype ; Karyotyping ; Medical Records ; Nuchal Translucency Measurement* ; Pregnancy ; Pregnancy Trimester, First ; Pregnancy Trimester, Second ; Prevalence ; Retrospective Studies ; Trisomy

Genetic ultrasonography refers to the evaluation of risk of chromosomal abnormalities via various soft sonographic markers. Although the maternal serum test is the primary screening method for chromosomal abnormalities, genetic ultrasonography is also widely used and can help increase detection rates. To date, many soft markers, including choroid plexus cysts, echogenic intracardiac foci, mild ventriculomegaly, nuchal fold thickening, echogenic bowel, mild pyelectasis, short femur and humerus length, and absent or hypoplastic nasal bone, have been reported. An aberrant right subclavian artery was the most novel soft marker introduced. Because these soft markers involve diverse relative risks of chromosomal abnormalities, it is difficult to apply them to clinical practice. To optimize the efficacy of genetic ultrasonography, it is important to understand the precise relative risks of chromosomal abnormalities innumerous soft markers and integrate these risks with each other and the results of maternal serum screening.
Choroid Plexus ; Chromosome Aberrations* ; Down Syndrome ; Echogenic Bowel ; Femur ; Humerus ; Mass Screening ; Nasal Bone ; Nuchal Translucency Measurement ; Pyelectasis ; Subclavian Artery ; Ultrasonography*

Chorionic villus sampling has gained importance as a tool for early cytogenetic diagnosis with a shift toward first trimester screening. First trimester screening using nuchal translucency and biomarkers is effective for screening. Chorionic villus sampling generally is performed at 10-12 weeks by either the transcervical or transabdominal approach. There are two methods of analysis; the direct method and the culture method. While the direct method may prevent maternal cell contamination, the culture method may be more representative of the true fetal karyotype. There is a concern for mosaicism which occurs in approximately 1% of cases, and mosaic results require genetic counseling and follow-up amniocentesis or fetal blood sampling. In terms of complications, procedure-related pregnancy loss rates may be the same as those for amniocentesis when undertaken in experienced centers. When the procedure is performed after 9 weeks gestation, the risk of limb reduction is not greater than the risk in the general population. At present, chorionic villus sampling is the gold standard method for early fetal karyotyping; however, we anticipate that improvements in noninvasive prenatal testing methods, such as cell free fetal DNA testing, will reduce the need for invasive procedures in the near future.
Amniocentesis ; Biomarkers ; Chorionic Villi Sampling* ; Cytogenetics ; Diagnosis ; DNA ; Extremities ; Female ; Fetal Blood ; Genetic Counseling ; Humans ; Karyotype ; Karyotyping ; Mass Screening ; Mosaicism ; Nuchal Translucency Measurement ; Pregnancy ; Pregnancy Trimester, First