To report the phenotype of patients with AME by clinical and biochemical study, and expanding the study to their families and unrelated subjects to assess the value of F/E ratio as a biomarker partial deficiency of 11βHSD2.Design and Method:
We evaluated 2 AME patients and their families. Family 1: A 17 years-old male with a homozygous Asp223Asn (D223N) mutation in HSD11B2, his mother (33 years) and sister (8 years); and Family 2: A 2 years-old girl with a homozygous Arg213Cys (R213C) mutation in HSD11B2, his father (30 years), her mother (30 years) and sister (6 years). We measured serum potassium, aldosterone, plasma renin activity (PRA), microalbuminuria, NGAL and F/E ratio (HPLC-MS). Reference ranges (RR), percentiles (p) and cut-off points for F, E and F/E serum were determined on data obtained from adult and pediatric normotensive subjects (F/E children RR: 1.63 to 5.15 and F/E adults RR:2.6–7.8]). Genetic analyses were performed by PCR-HRM and DNA sequencing.Results:
Family 1: Index case (mut D223N) with classical AME features and a high serum F/E ratio (28.8 (> p99)). His mother and sister were normotensive and heterozygous for the same mutation D223N without clinical and biochemical abnormalities but with high F/E ratios (13.1 (p97) and 7.4 (p97)), respectively). Family 2: Index case (mut R213C) with classical AME and and a high F/E (175 (>p99)). His father, mother and sister were heterozygous for R123C, and are clinically and biochemically normal except for high F/E ratios (p92, p93 and p85, respectively).Conclusions:
A F/E ratio greater than p90 –often associated to a cortisone lesser than p30- in relatives of subjects with AME suggests that partial heterozygous alterations or deficit in HSD11B2 are able to be identified by studying the serum cortisone and F/E ratio without prior clinical or biochemical features of classic AME such as AH, suppressed PRA and hypokalemia.