Table 2.

Summary of effects of rare variants on PRLR function.

	PRLR variant	Predicted pathogenicity			STAT5 signalling		PI3K/ Akt signalling		Cell viability	Apoptosis
		Prediction programsa	Evolutionary conservationb	Structural predictions	pSTAT5	CISH	pAkt	FOXO1
	WT	0	N/A	N/A	++	++	++	++	++	++
	His188Arg	4	4	Affects PRL binding	-	-	-	-	++	+++
ECD	Tyr99His	3	4	Affects PRL binding	+	+	++	++	++	++
	ECD	Glu145Asp	3	4	Loss and gain of contacts	++	++	++	++	++	++
	ECD	Glu155Lys	3	3	Disrupts homodimer region	+	+	++	+	++	++
	ECD	Arg183His	2	4	Loses contact with WSxWS motif	++	++	++	++	++	++
	ECD	Asp187Glu	3	4	Loses contact with His188	-	+	+	++	++	++
ICD	Phe255Ser	4	4	LID1, close to JAK2 binding site	-	+	++	++	+++	++
	ICD	Gly263Asp	4	4	LID1	++	++	++	++	++	++
	ICD	Asp320Tyr	2	4	Unknown	++	++	++	++	++	++
	ICD	Arg327Gln	1	2	Degradation motif	+++	+++	+*	++	+++	++
	ICD	Val535Met	4	4	Unknown	++	++	++	++	++	++

^aA score out of four based on protein predictions using SIFT, Polyphen-2, MutationTaster, and REVEL is given. If the variant was predicted to be probably damaging or damaging/pathogenic, it was classified as affected; ^bEvolutionary conservation was based on the PRLR ortholog sequence in four species (cow, dog, mouse, and rat) in comparison to the human protein. The score shows the number of species in which the residue is conserved out of 4; ⁺⁺⁺Gain of function; ⁺⁺Normal; ⁺Impaired; ^-Abolished.;^*Arg327Gln has significantly increased basal Akt activity, which likely accounts for the impaired PRL-induced activity.

N/A, not applicable.