Side-chain cleavage enzyme deficiency: Systematic review and case series.

OBJECTIVE: P450 side-chain cleavage deficiency (SCCD) patients present with primary adrenal insufficiency (PAI) with or without undervirilized external genitalia. The distinction between classic and nonclassic steroidogenic acute regulatory protein deficiency has been described, whereas in SCCD is unclear. The data on gonadal function and its correlation with SCCD genotype has not been studied. We describe our experience and perform a systematic review of genetically proven SCCD patients to determine the distinct phenotypic and genotypic characteristics of 46,XY SCCD patients with typical male external genitalia (SCCD-TMG) and atypical (SCCD-AG) external genitalia. DESIGN, PATIENTS AND MEASUREMENTS: Retrospective review of three genetically proven SCCD patients from our centre and per-patient data analysis from a systematic review of 52 probands was performed. SCCD-TMG (n = 19) was defined as external genitalia of Sinnecker score 1 with 46,XY  karyotype; the rest (Sinnecker 2-5) were classified as SCCD-AG (n = 15). RESULTS: We report two new Indian cases of SCCD with three novel likely pathogenic variants and pubertal follow-up of a previously reported patient. In systematic review, age at diagnosis of PAI and elevated renin were not different between 46,XY  SCCD-TMG (n = 19) and SCCD-AG (n = 15), whereas spontaneous puberty (9/9 vs. 0/3, p = .0045), normal prepubertal (5/5 vs. 6/6, p = .002), pubertal gonadotropins (2/9 vs. 0/3, p = 1) and normal pubertal testosterone (9/11 vs. 0/3, p = .027) were more common in SCCD-TMG. Testicular adrenal rest tumours were exclusive to SCCD-TMG (n = 4). SCCD-TMG was associated with four particular genotypes [monoallelic p.Glu314Lys with another deleterious variant on the second allele (p.Glu314Lys/X-CHS: X-compound heterozygous state), biallelic p.Arg451Trp, p.Phe215Ser/p.Arg232Ter and monoallelic p.Val79Ile]. 46,XX SCCD  patients with p.Glu314Lys/X-CHS also had normal gonadotropins with spontaneous puberty. CONCLUSION: SCCD-TMG is associated with four specific genotypes and distinct gonadal characteristics from SCCD-AG with overlapping features of PAI.

17α-Hydroxylase/17,20-Lyase Deficiency in 46,XY: Our Experience and Review of Literature.

CONTEXT: There are more than 100 pathogenic variants in CYP17A1 that have been identified in patients with 17α-hydroxylase/17,20-lyase deficiency (17OHD). OBJECTIVE: We aimed to describe 46,XY patients with 17OHD from our center and review the literature. METHODS: We retrospectively analyzed genetically proven index cases of 17OHD from our 46,XY disorders of sex development cohort and reviewed similar cases from the literature (n = 150). Based on the phenotype, 17OHD probands were classified into combined severe deficiency (n = 128) and combined partial deficiency (n = 16). Additionally, patients with the apparent isolated 17,20-lyase deficiency (n = 7, from 6 families) were noted. Residual enzyme activities with the observed mutant enzymes were divided in 2 categories as < 1% and ≥ 1%, each for hydroxylase and lyase. RESULTS: We present 4 index cases of 46,XY 17OHD with a complete spectrum of undervirilization and 2 novel variants in CYP17A1. In the review, the combined severe deficiency was the most common form, with more frequent female sex of rearing, hypertension, hypokalemia, suppressed renin, higher plasma corticotropin, lower serum cortisol, and androgens. Immunoassay-measured serum aldosterone was frequently (68.2%) unsuppressed (>5 ng/dL). Elevated serum progesterone had high sensitivity for diagnosis of combined 17OHD, even in combined partial deficiency (83.3%). Among patients with clinical phenotype of combined severe deficiency, 11.5% had partial 17α-hydroxylase and complete 17,20-lyase deficiency (>1%/<1%) and had significantly higher serum cortisol than those with < 1%/<1% activity. CONCLUSION: We report the first monocentric case series of Asian Indian 46,XY patients with 17OHD. We propose that a phenotype of severe undervirilization with milder cortisol deficiency may represent a distinct subtype of combined severe 17OHD with residual 17α-hydroxylase activity but severe 17,20-lyase deficiency (>1%/<1%), which needs further validation.