Polymorphisms of the IGF-I gene in children born small for gestational age (SGA).

SILVANO L, PEREZ A, MARTIN S, PICOTTO G, DIAZ G, MUÑOZ L, PRETEL E, ET AL.

Mar del Plata

Congreso; Annual Meeting of the Sociedad Latinoamericana de Endocrinologia Pediátrica (SLEP),; 2007

We observed that SGA children without post-natal catch-up growth (SGAcg-) had serum IGF-I levels significantly lower than those in AGA children. It has been suggested that minor genetic variation in the IGF-I gene will be able to influence serum IGF-I levels resulting in affected fetal and postnatal growth. Several IGF-I polymorphisms have been identified though their functional significance is not clear. AIM: To analyze the frequency of IGF-I polymorphism and their association with variables of postnatal growth in SGA children. METHODS: 48 healthy prepubertal AGA children, mean CA 7.2 yr and 49 SGA children divided in 23 SGA with catch up growth, mean CA 7.0 yr SDS height -0.88 and 26 SGAcg-, mean CA 6.1 yr SDS height -2.27 were studied. Serum levels of IGF-I, IGF-II, IGFBP3, IGFBP1, ALS, osteocalcin, beta cross laps and lumbar and femoral BMD were determined. A cytosine-adenine repeat in the promotor region of the IGF-I gene were analyzed. Chi Squared Test was used. RESULTS: the most common polymorphisms were 192-192 (51 %), 194-192 (16%) and 196-192 (9%), and they were significantly different between the three groups (p=0.01). No important differences were found between the polymorphisms and the variables analyzed. CONCLUSIONS: Our results suggest that this IGF-I microsatellite do not count for the differences in the serum IGF system observed in this population. The real meaning of the different frequencies and their influence on the postnatal growth outcome and the body size will be analysed in further studies.