H. Zheng et al., G alpha s transcripts are biallelically expressed in the human kidney cortex: Implications for Pseudohypoparathyroidism type 1b, J CLIN END, 86(10), 2001, pp. 4627-4629
Pseudohypoparathyroid type 1b patients are characterized by renal resistanc
e to PTH in the absence of Albright's hereditary osteodystrophy or other en
docrine abnormalities. Kindred studies have suggested that the cause of thi
s resistance is a specific decrease in G alphas activity in renal proximal
tubules due to paternal imprinting of G alphas. To test this, allelic expre
ssion of G alphas was analyzed in human fetal kidney cortex samples by RT-P
CR assays. The results showed that, in contrast to the parent-specific expr
ession of exon 1A and XL alphas (paternal) or NESP (maternal) mRNAs, G alph
as transcripts are biallelically expressed in human kidney cortex. These da
ta implicate abnormal imprinting of alternative regions within the GNAS1 lo
cus as a more likely cause of pseudohypoparathyroid type 1b.