Genetic factors associated with small for gestational age birth and the use of human growth hormone in treating the disorder

Table 5 Summary of known genetic causes of SGA and the correlating response to hGH therapy [[11],[13],[16]-[18],[23],[25]-[29],[39]-[47],[51],[53]-[55],[57]-[62],[68],[70],[74]-[76],[78]-[80]]

Class of genetic mutation	Specific genetic variant	Response to hGH therapy
	IGF-1	Generally not effective
	IGF-1R	Good for partial distal deletions; generally not effective for point mutations
GH/IGF-1 axis	Point
	Distal
	ALS deletions	Good outcome for heterozygous carriers
	Obesity/diabetes-related genes	Unclear
Select Polymorphisms	Angiotensinogen gene	Unclear
	d3-GHR	Good outcome, but dose and age matter
	SRS	hGH therapy is commonly used for SRS, but correlation between effectiveness and specific genetic mutation has not been carefully evaluated
	Full mUPD7
UPD/imprinting effects	mUPD7 for long arm of chromosome 7
	Hypomethylation at ICR1 on 11p15
	Duplication of ICR2 on 11p15
	UPD14	Unclear

ALS, acid-labile subunit; ICR, imprinting control region; IGF-1, insulin-like growth factor-1; d3-GHR, deletion of exon 3 growth hormone receptor; hGH, human growth hormone; SGA, small for gestational age; SRS, Silver-Russell syndrome; UPD, uniparental disomy.

ISSN: 1687-9856