Two patients with a complete absence of biologically active IGF-1 showed severe pre- and postnatal growth, extreme microcephaly, sensorineural deafness and failure to thrive.
Intrauterine and postnatal growth retardation, microcephaly and IGF-1 levels above the mean of age references are consistent findings in these patients, although IGF-1 levels can be low initially because of feeding problems.
She had, in addition, pre- and post-natal growth impairment (<3rd percentile), severe microcephaly (<-3 SD) with normal gyration pattern and lack of cortical thickening associated with a hypoplastic inferior vermis, facial dysmorphism, sensorineural deafness and decreased serum levels of IGF-1.