Familial Study of Paracentric Inversion in Chromosome 3p

Aims: To describe the familial occurrence of paracentric inversion of chromosome 3.
Presentation of Cases: Patient 1: Female, Caucasian, born in Southeast of Brazil, 7 years old. Born at term and asphyxia. Developmental delay; aggressive behavior and tendency toward isolation. Prominent forehead, discrete epicanthal folds, down-slanting palpebral fissures, long philtrum and hypermobility of the four limbs. Karyotype: 46,XX,inv(3)(p13p25). Patient 2: Female, Caucasian, born in Northeast of Brazil, 3 years old. Born prematurely by cesarean section, pelvic presentation and asphyxia. Severe developmental delay. Microcephaly, bilateral convergent strabismus, epicanthal folds, wide nasal bridge, micrognathia, high arched palate and nasolabial hemangioma, low set ears, hypoplastic nipples, nucal café-au-lait spots, deep plantar fold. Dysgenesis of the corpus callosum. Karyotype: 46,XX,inv(3)(p13p25). Patient 3: Male, Caucasian, born in Southeast of Brazil, 5 years. Born at term, by cesarean section, cephalic presentation. Developmental delay and flexor spasms. Dolichocephalic skull, prominent forehead, ocular hypertelorism, epicanthal folds, disproportioned and low set ears, single palmary crease in the right hand, large and elongated thumbs, hypotonia, and recurrent acute otitis. Karyotype: 46,XY,inv(3)(p13p25).
Discussion: Patients presented developmental delay and dysmorphic features, but the relatives that presented the same inversion were asymptomatic. Carriers seem to have a normal reproductive fitness, without differences between males and females.
Conclusion: The chromosomal rearrangements, especially balanced chromosomal alterations provide an opportunity to broaden the understanding of the structure and functional organization of chromosomes and to offer better genetic counseling for the families.