the end of the DSD spectrum, and in some cases are not included as DSD, even if in some cases, they represent a milder effect of the same etiology seen in severe DSD. Clinical features that indicate DSD usually include isolated clitoral hypertrophy, isolated posterior hypospadias, bilateral cryptorchidism or ectopia, and unilateral cryptorchidism/testicular ectopic associated with hypospadias or micro-penis; these signs are often seen in the newborn period [5; 6]. Signs that suggest DSD at puberty are virilization of initially female genitalia, pubertal delay, and primary amenorhea [5; 6]. Usually, the clinical investigation aims to examine the following: genital tubercle (size and aspect), labioscrotal folds (their posterior fusion), the urinary meatus (localization), and palpable gonads. Based on these data, the Prader stages--a masculinization scale of the external genitalia and anogenital distance--could be useful indices for the degree of genital virilization [5; 6; 7]. Clinical evaluation of the external genitalia is always followed by an imaging evaluation to describe the characteristics of the urogenital sinus, Mullerian structures, gonads, adrenal glands, and sometimes, the renourinary system (to determine the common embryonic origin). This evaluation usually is performed using ultrasounds and MRI, although genitography/genitoscopy or even exploratory laparoscopy and histopathological examination are utilized in some situations [8]. DSD are classified depending on karyotype (i.e., 46,XY DSD; 46,XX DSD; and sex chromosome DSD), and in some cases, DSD is observed as part of other developmental disorders (e.g., syndromic DSD) [9]. 46,XY and 46,XX DSD could be the results of abnormal gonadal development or disorders of steroid synthesis and action. 46,XX disorders of ovarian development include 46,XX testicular and ovotesticular DSD, which are caused by _SRY_ translocation in 85% of testicular 46,XX and 10% of ovotesticular 46,XX, as well as _SOX9_, _RSVO1_, or _SOX3_ disorders. They also include 46,XX gonadal dysgenesis, which, in cases of premature ovarian failure, is due to genes involved in gonadal development, such as _FSHR_, _NRSA1_, _BMP15_, _STAG3_, and _WT1_[9; 10]. 46,XY disorders of testicular development include complete and partial gonadal dysgenesis, which are due more often to _SRY_ gene abnormalities and less often to _DHH_, _NRSA1_, _MAP3K1_, _CBX2_, _NROB1_, _WNT4_, or _DMRT1_ gene abnormalities [9; 10]. Sex chromosome DSD includes [PERSON] syndrome (45,X and variants); [PERSON] syndrome (47,XXY and variants); mosaic 45,X/46,XY (mixed gonadal dysgenesis); 46,XX/46,XY (ovotesticular DSD); and other aneuploidies involving sex chromosomes [9]. DSD may not be an endocrine disorder but rather a developmental one, such as cloacal extrophy (omphalocele-exstrophy-imperforate aus-spinal defects-OEIS spectrum (in 46,XX and 46,XY DSD) and developmental abnormalities of the Mullerian structures (e.g., hypospadias in 46,XY DSD or Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome, vaginal atresia, and Mullerian agenesis in 46,XX DSD). In cases of 46,XX and 46,XY disorders of steroid hormone biosynthesis, _CYP21A2_ gene mutations are the most common cause (>90% of these cases). Genetic mutations found among the remainder include: _STAR_ (46,XY DSD), _3-BHSD_ (46,XY DSD), _CYP1A1_ (46,XY DSD), _CYP1B1_ (46,XX DSD), _POR_ (46,XX and 46,XY DSD), _CYP1A1_ (46,XY DSD), _CYP1A1_ (46,XX DSD), _5 ARD_ (46,XY DSD), _or 17\(\beta\)HSD3_ (46,XY DSD) [9]. Disorders of steroid hormone action in 46,XY patients are most often due to gene mutations in _AR_, _AMHR_, or _LHR_ abnormalities. Morphologic assessment is always based on biochemical and genetic analysis. Biochemical analysis refers primarily to steroid analysis, such as plasma 17-hydroxyprogesterone, testosterone, dihydrotestosterone, androstenedione, DHEA, DHEAs, deoxycorticosterone, plasma renin activity, ACTH, FSH, LH, AMH, and urinary/24-h evaluation of urinary steroid profile (performed by gas chromatography associated with mass spectrometry [GC/MS]) [11].