Table 1. Genes or proteins that have been correlated with sperm retrieval rate.

Name	Details	SRR outcomes	Additional information	Source
Genetic markers using RT-PCR on testicular biopsies
AZF	AZFa – USP9Y and DBY	Very poor	Complete AZFa deletion causes Sertoli-cell only syndrome (SCOS) Deletion of USP9Y only results in hypospermatogenesis	51 54
	AZFb – RBMY and PRY	Very poor	Corresponds with maturation arrest in histology	52
	AZFc – 12 genes	33–87%	Common, wide phenotypic ranges from SCOS to normospermatogenesis	53,54,56
JMJD1A	Jumonji domain-containing 1a	Positive	n = 22 Sensitivity 91%, specificity 89%	57
RNF8	E3 ubiquitin ligase Chr 6p21.3	Positive	n = 47 Sensitivity 81%, specificity 84%	58
SPEM1	Post-meiotic marker, testes- specific gene	Positive	n = 63 Sensitivity 96%, specificity 85%	59
VASA	Chr 5q, expressed specifically in germ cells	Positive	n = 52 Sensitivity 87%, specificity 86% Independent predictor after multivariant analysis	60
Protein markers in seminal plasma
Clusterin	Apolipoprotein J, secreted by Sertoli cells	Positive	Seminal Clusterin in conjunction with FSH levels associated with successful TESE (n = 89), with reduced risk of abnormal spermatozoa and DNA fragmentation, although this may be confounded by hypertension	61 62 63
LGAL3BP	Lectin galactoside-binding, soluble 3 binding protein	Positive	Seminal LGAL3BP is higher in men with successful TESE n = 40 Sensitivity 100%, specificity 45%	64
HE1	Epididymal secretory protein E1, cholesterol transporter	Positive* IVF	Higher levels associated with successful IVF n = 13	65
TEX101	Cell membrane protein exclusive to testicular germ cell	Positive	n = 137 Sensitivity 73%, specificity 64% Proposed use of two marker algorithm ECM1 and TEX101	66 67

FSH, follicle-stimulating hormone; IVF, in vitro fertilisation; RT-PCR, real-time polymerase chain reaction; SRR, sperm retrieval rate; TESE, testicular sperm extraction.