ABSTRACT
The only known twin pair evidently discordantly affected for the BDLS (Brachmann-de Lange syndrome) and who had been considered monozygotic (MZ) based on blood analysis remained a problem because biological zygosity determination needed further typing. In this report we review the clinical findings of this pair of twins at the age of 20. The use of DNA fingerprinting with three multilocus probes, F10, DNF24, and 33.6, allowed us to present evidence of monozygosity with a high degree of certainty. The significance of this confirmation of discordance in determining the cause of BDLS is discussed. Intensive comparative genomic studies of the discordant twin sisters may be useful to unravel the molecular genetics of this enigmatic pattern of malformation.
Subject(s)
De Lange Syndrome/genetics , Twins, Monozygotic , Adult , Chromosome Banding , Chromosomes, Human, Pair 3 , DNA Fingerprinting , De Lange Syndrome/complications , Diseases in Twins , Face/abnormalities , Female , Follow-Up Studies , Head/abnormalities , Humans , Intellectual Disability/complications , Intellectual Disability/geneticsABSTRACT
Descrevem-se as características das hemácias A3 com métodos convencionais e ulteriores testes com lectinas vegetais e de caramujos. Dos três indivíduos estudados, Mulato Claro, dois nasceram em Pernambuco e um no Rio de Janeiro. A separaçäo das hemácias A3 sugere uma mistura de, pelo menos, duas populaçöes de células com aglutinabilidade variável do antígeno A. Uma análise da literatura permitiu estimar que a maior freqüência de A3 encontrou-se em Negroides, um valor intermedio em Caucasoides e a menor prevalência em pessoas do Estado de Maharashtra na India
