Table 1.

Summary of clinical findings

SubjectA-I-2A-II-2A-III-1A-III-2A-III-3A-III-4B-I-2B-II-1B-II-2B-III-1B-III-2
GNAS-GsαVTaVTaWTVTaVTaVTaNEWTVTbVTbVTb
SexWWMWWWWMWMW
Present age, yr775031282213695442159
NSIAD (AVPR2 related)YesYesNoUncertainYesYesUncertainNoYesUncertainYes
Febrile and/or afebrile convulsions with hyponatremia+++++
Hyponatremia+++++±+
Low serum osmolality under low plasma AVP+++++±+
High urine osmolality under low plasma AVP+++++±+++
Amelioration of hyponatremia by fluid restrictioncNENENENE+NENENENENE+
Urine excretion failure in an acute oral water load testd++++NENENENENENE
Growth pattern (GHRHR related)WNRWNRWNRWNRWNRWNRWNRWNRWNRWNRWNR
Gonadal function (FSHR/LHCGR related)WNR (fertile)WNR (fertile)NEWNRWNRWNRWNR (fertile)WNR (fertile)WNR (fertile)NEWNR
Calcium metabolism (PTH1R related)WNRWNRNEWNRWNRHypocalciuria (subclinical)NENENENEWNR
Thyroid function (TSHR related)WNRElevated (subclinical)WNRWNRElevated (subclinical)Elevated (subclinical)NENENENEElevated (subclinical)
MAS findings
Other abnormal phenotype
  • Besides the G-protein-coupled receptors (GPCRs) shown in this table, Gsa mediates signal transductions of other GPCRs. GNAS-Gsα, G-protein α-subunit encoded by GNAS exons 1–13; VT, variant; WT, wild-type; NE, not examined; W, woman; M, man; NSIAD, nephrogenic syndrome of inappropriate antidiuresis; AVPR2, arginine vasopressin receptor 2; AVP, arginine vasopressin; GHRHR, growth hormone–releasing hormone receptor; WNR, within the normal range; FSHR, follicle-stimulating hormone receptor; LHCGR, luteinizing hormone/choriogonadotropin receptor; PTH1R, parathyroid hormone 1 receptor; TSHR, thyroid-stimulating hormone receptor; MAS, McCune–Albright syndrome; +, positive; +/−, equivocal; −, negative.

  • a p.(F68_G70del).

  • b p.(M255V).

  • c 60 ml/kg per day for 2 days immediately after hyponatremic convulsions.

  • d 20 ml/kg per os over 30 minutes; blood and urine sampling at 60- and 30-minute intervals, respectively, for 4 hours.