Characterization of a novel growth hormone receptor-encoding cDNA in rainbow trout and regulation of its expression by nutritional state.

To clarify the divergence of the growth hormone receptor (GHR) family, we characterized a novel GHR from a teleost fish (rainbow trout). A 2357-nt cDNA was isolated and found to contain a single initiation site 71 nt from the most 5' end, an open reading frame of 1971 nt encoding a 657-amino acid protein, and a single polyadenylation site 229 nt from the poly-A tail. Based on structural analysis, the protein was identified as a type 1 GHR (GHR1). The new GHR1 shares 42% and 43% amino acid identity, respectively, with GHR2a and GHR2b, the two type 2 GHRs isolated from trout previously. GHR1 mRNA was found in a wide array of tissues with the highest expression in the liver, red muscle, and white muscle. Fasting animals for 4 weeks reduced steady state levels of GHR1 in the liver, adipose, and red muscle. These findings help clarify the divergence and nomenclature of GHRs and provide insight into the function of duplicated GHR types.

Novel α-galactosidase A mutation in patients with severe cardiac manifestations of Fabry disease.

Fabry disease (FD) is a hereditary metabolic disorder caused by the partial or total inactivation of α-galactosidase A (α-gal A), a lysosomal hydrolase. This inactivation is responsible for the accumulation of undegraded glycosphingolipids in the lysosomes with subsequent cellular and microvascular dysfunction. Fabry is considered a rare disease, with an incidence of 1:40,000; however, there are good reasons to believe that it is often seen but rarely diagnosed. To date, more than 600 mutations have been identified in human GLA gene that are responsible for FD. We describe the case of a 54-year-old male patient, who presented with left ventricular hypertrophy, chronic renal failure and acroparaesthesias, which are considered to be specific features of FD. Clinical and instrumental investigations showed several cardiovascular manifestations. The molecular analysis of GLA gene revealed a novel mutation in the fifth exon, called N249K, and the enzymatic analysis showed no α-galactosidase A activity. Family screening detected the same mutation in some relatives and also the enzymatic analysis confirmed the diagnosis of FD. In conclusion, these data suggest that the N249K mutation may be associated with cardiac manifestations of FD combined with other classical features of the disease.