ABSTRACT
Thanatophoric dysplasia (TD) is a sporadic lethal type of skeletal dysplasia featuring micromelia, decreased thoracic dimension and macrocephaly. To date, several kinds of mutation in fibroblast growth factor receptor 3 (FGFR3) has been identified in TD. We experienced a case of TD type I and underwent sequencing of the exon 7, 10 and the stop codon of FGFR3 to identify the type of mutation. TDI was diagnosed by the prenatal ultrasound at 25 weeks of gestation. The pregnancy was terminated and the diagnosis was confirmed by radiological and histologic examinations. The genomic DNA was extracted and the sequences of the exon 7, 10 and the stop codon of FGFR3 were amplified by PCR. The sequencing was performed for the each PCR products by dideoxyterminator method. The nucleotide transition from G to T was found in the nucleotide 1108, which is a part of the transmembrane domain, exon 10. To date, only one type of mutation (nucleotide 742) in the FGFR3 was identified in TD1 among Asian. This case firstly reveals the mutation of FGFR3 other than mutation at nucleotide 742 in TD1.
Subject(s)
Humans , Pregnancy , Asian People , Codon, Terminator , Diagnosis , DNA , Exons , Fibroblast Growth Factors , Fibroblasts , Megalencephaly , Polymerase Chain Reaction , Receptor, Fibroblast Growth Factor, Type 3 , Receptors, Fibroblast Growth Factor , Thanatophoric Dysplasia , UltrasonographyABSTRACT
OBJECTIVE: To assess the reliability of triple marker screening test in midtrimester pregnancy for fetal Down syndrome. METHODS: From October 1, 1996 to May 31, 1998 at Nowon Eulji Hospital, 3700 Pregnant women underwent serum tiple marker screening for Down syndrome during 15-20weeks of gestational age. The results of serum triple marker screenig tests for Down syndrome and the outcomes of pregnancies were retrospectively assesed. RESULTS: Sixty seven of 3700 cases(1.81%) were positive in screening test, and 3633(98.18%) cases were negative. Among 67 cases of positive screening test, 1 case(1.49%) was diagnosed as Down syndrome. Among 3633 cases of negative screening test, 4 cases(0.1%) were diagnosed as chromosomal abnormalies postnatally. Two of these 4 cases of chromosomal abnormalies were Down syndrome. CONCLUSION: With this results, sensitivity of triple marker screeing test for Down syndrome is very low as 33.3%. In order to increase the sensitivity, some compensatory adjustment is required in triple marker screening test.