The PROP1 2-Base Pair Deletion Is a Common Cause of Combined Pituitary Hormone Deficiency

Combined pituitary hormone deficiency (CPHD) has an incidence of approximately 1 in 8000 births.Although the proportion of familial CPHD cases is unknown, about 10% have an affected first degree relative.We have recently reported three mutations in the PROP1 gene that cause CPHD in human subjects.We report here the frequency of one of these mutations, a 301-302delAG deletion in exon 2 of PROP1, in 10 independently ascertained CPHD kindreds and 21 sporadic cases of CPHD from 8 different countries.Our results show that 55% (11 of 20) of PROP1 alleles have the 301-302delAG deletion in familial CPHD cases.Interestingly, although only 12% (5 of 42) of