scholarly journals The laboratory in the multidisciplinary diagnosis of differences or disorders of sex development (DSD)

Author(s):  
Maria Luisa Granada ◽  
Laura Audí

Abstract Objectives The development of female or male sex characteristics occurs during fetal life, when the genetic, gonadal, and internal and external genital sex is determined (female or male). Any discordance among sex determination and differentiation stages results in differences/disorders of sex development (DSD), which are classified based on the sex chromosomes found on the karyotype. Content This chapter addresses the physiological mechanisms that determine the development of female or male sex characteristics during fetal life, provides a general classification of DSD, and offers guidance for clinical, biochemical, and genetic diagnosis, which must be established by a multidisciplinary team. Biochemical studies should include general biochemistry, steroid and peptide hormone testing either at baseline or by stimulation testing. The genetic study should start with the determination of the karyotype, followed by a molecular study of the 46,XX or 46,XY karyotypes for the identification of candidate genes. Summary 46,XX DSD include an abnormal gonadal development (dysgenesis, ovotestes, or testes), an androgen excess (the most frequent) of fetal, fetoplacental, or maternal origin and an abnormal development of the internal genitalia. Biochemical and genetic markers are specific for each group. Outlook Diagnosis of DSD requires the involvement of a multidisciplinary team coordinated by a clinician, including a service of biochemistry, clinical, and molecular genetic testing, radiology and imaging, and a service of pathological anatomy.

2021 ◽  
pp. 1-9
Author(s):  
Franco G. Brunello ◽  
Rodolfo A. Rey

Anti-müllerian hormone (AMH) is 1 of the 2 testicular hormones involved in male development of the genitalia during fetal life. When the testes differentiate, AMH is secreted by Sertoli cells and binds to its specific receptor type II (AMHR2) on the müllerian ducts, inducing their regression. In the female fetus, the lack of AMH allows the müllerian ducts to form the fallopian tubes, the uterus, and the upper part of the vagina. The human <i>AMH</i> gene maps to 19p13.3 and consists of 5 exons and 4 introns spanning 2,764 bp. The <i>AMHR2</i> gene maps to 12q13.13, consists of 11 exons, and is 7,817 bp long. Defects in the AMH pathway are the underlying etiology of a subgroup of disorders of sex development (DSD) in 46,XY patients. The condition is known as the persistent müllerian duct syndrome (PMDS), characterized by the existence of a uterus and fallopian tubes in a boy with normally virilized external genitalia. Approximately 200 cases of patients with PMDS have been reported to date with clinical, biochemical, and molecular genetic characterization. An updated review is provided in this paper. With highly sensitive techniques, AMH and AMHR2 expression has also been detected in other tissues, and massive sequencing technologies have unveiled variants in <i>AMH</i> and <i>AMHR2</i> genes in hitherto unsuspected conditions.


2021 ◽  
pp. 1-19
Author(s):  
Gabby Atlas ◽  
Rajini Sreenivasan ◽  
Andrew Sinclair

Disorders of sex development (DSD) are a complex group of conditions with highly variable clinical phenotypes, most often caused by failure of gonadal development. DSD are estimated to occur in around 1.7% of all live births. Whilst the understanding of genes involved in gonad development has increased exponentially, approximately 50% of patients with a DSD remain without a genetic diagnosis, possibly implicating non-coding genomic regions instead. Here, we review how variants in the non-coding genome of DSD patients can be identified using techniques such as array comparative genomic hybridization (CGH) to detect copy number variants (CNVs), and more recently, whole genome sequencing (WGS). Once a CNV in a patient’s non-coding genome is identified, putative regulatory elements such as enhancers need to be determined within these vast genomic regions. We will review the available online tools and databases that can be used to refine regions with potential enhancer activity based on chromosomal accessibility, histone modifications, transcription factor binding site analysis, chromatin conformation, and disease association. We will also review the current in vitro and in vivo techniques available to demonstrate the functionality of the identified enhancers. The review concludes with a clinical update on the enhancers linked to DSD.


2018 ◽  
Vol 179 (4) ◽  
pp. R197-R206 ◽  
Author(s):  
L Audí ◽  
S F Ahmed ◽  
N Krone ◽  
M Cools ◽  
K McElreavey ◽  
...  

The differential diagnosis of differences or disorders of sex development (DSD) belongs to the most complex fields in medicine. It requires a multidisciplinary team conducting a synoptic and complementary approach consisting of thorough clinical, hormonal and genetic workups. This position paper of EU COST (European Cooperation in Science and Technology) Action BM1303 ‘DSDnet’ was written by leading experts in the field and focuses on current best practice in genetic diagnosis in DSD patients. Ascertainment of the karyotpye defines one of the three major diagnostic DSD subclasses and is therefore the mandatory initial step. Subsequently, further analyses comprise molecular studies of monogenic DSD causes or analysis of copy number variations (CNV) or both. Panels of candidate genes provide rapid and reliable results. Whole exome and genome sequencing (WES and WGS) represent valuable methodological developments that are currently in the transition from basic science to clinical routine service in the field of DSD. However, in addition to covering known DSD candidate genes, WES and WGS help to identify novel genetic causes for DSD. Diagnostic interpretation must be performed with utmost caution and needs careful scientific validation in each DSD case.


2020 ◽  
Vol 66 (3) ◽  
pp. 62-69
Author(s):  
Natalia Yu. Kalinchenko ◽  
Anna A. Kolodkina ◽  
Nadezda Y. Raygorodskaya ◽  
Anatoly N. Tiulpakov

Steroidogenic factor 1 (SF1, NR5A1) is a nuclear receptor that regulates multiple genes involved in adrenal and gonadal development, steroidogenesis, and the reproductive axis. Human mutations in SF1 were initially found in patients with severe gonadal dysgenesis and primary adrenal failure. However, more recent case reports have suggested that heterozygous mutations in SF1 may also be found in patients with 46,XY partial gonadal dysgenesis and underandrogenization but normal adrenal function. We have analyzed the gene encoding SF1 (NR5A1) in a cohort of 310 Russian patients with 46,XY disorders of sex development (DSD). Heterozygous SF1 variants were found in 36 out of 310 (11.6%) of cases, among them 15 were not previously described. We have not found any phenotype-genotype correlations and any clinical and laboratory markers that would allow to suspect this type of before conducting molecular genetic analysis.


2021 ◽  
pp. 1-9
Author(s):  
Maria T.M. Ferrari ◽  
Andreia Watanabe ◽  
Thatiane E. da Silva ◽  
Nathalia L. Gomes ◽  
Rafael L. Batista ◽  
...  

Wilms’ tumor suppressor gene 1 (<i>WT1</i>) plays an essential role in urogenital and kidney development. Heterozygous germline pathogenic allelic variants of <i>WT1</i> have been classically associated with Denys–Drash syndrome (DDS) and Frasier syndrome (FS). Usually, exonic pathogenic missense variants in the zinc finger region are the cause of DDS, whereas pathogenic variants affecting the canonic donor lysine-threonine-serine splice site in intron 9 cause FS. Phenotypic overlap between <i>WT1</i> disorders has been frequently observed. New <i>WT1</i> variant-associated phenotypes, such as 46,XX testicular/ovarian-testicular disorders of sex development (DSD) and primary ovarian insufficiency, have been reported. In this report, we describe the phenotypes and genotypes of 7 Brazilian patients with pathogenic <i>WT1</i> variants. The molecular study involved Sanger sequencing and massively parallel targeted sequencing using a DSD-associated gene panel. Six patients (5 with a 46,XY karyotype and 1 with a 46,XX karyotype) were initially evaluated for atypical genitalia, and a 46,XY patient with normal female genitalia sought medical attention for primary amenorrhea. Germ cell tumors were identified in 2 patients, both with variants affecting alternative splicing of <i>WT1</i> between exons 9 and 10. Two pathogenic missense <i>WT1</i> variants were identified in two 46,XY individuals with Wilms’ tumors; both patients were &#x3c;1 year of age at the time of diagnosis. A novel <i>WT1</i> variant<i>,</i> c.1453_1456 (p.Arg485Glyfs*14), was identified in a 46,XX patient with testicular DSD. Nephrotic proteinuria was diagnosed in all patients, including 3 who underwent renal transplantation after progressing to end-stage kidney disease. The expanding phenotypic spectrum associated with <i>WT1</i> variants in XY and XX individuals confirms their pivotal role in gonadal and renal development as well as in tumorigenesis, emphasizing the clinical implications of these variants in genetic diagnosis.


2018 ◽  
Vol 18 (1) ◽  
pp. 35-41
Author(s):  
J Gecz ◽  
J Breza ◽  
P Banovcin

Abstract Non-syndromic 46,XY DSD (disorders of sex development) represent a phenotypically diversiform group of disorders. We focus on the association between gene variants and the most frequent types of non-syndromic 46,XY DSD, options of molecular genetic testing which has surely taken its place in diagnostics of DSD in the past couple of years. We emphasize the need of molecular genetic testing in individuals with non-syndromic 46,XY DSD in Slovak Republic.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Prisca Amolo ◽  
Paul Laigong ◽  
Anjumanara Omar ◽  
Stenvert Drop

Objective. The purpose of this study was to describe baseline data on etiological, clinical, laboratory, and management strategies in Kenyan children and adolescents with Disorders of Sex Development (DSD). Methods. This retrospective study included patients diagnosed with DSD who presented at ages 0–19 years from January 2008 to December 2015 at the Kenyatta National (KNH) and Gertrude’s Children’s (GCH) Hospitals. After conducting a search in the data registry, a structured data collection sheet was used for collection of demographic and clinical data. Data analysis involved description of the frequency of occurrence of various variables, such as etiologic diagnoses and patient characteristics. Results. Data from the records of 71 children and adolescents were reviewed at KNH (n = 57, 80.3%) and GCH (n = 14, 19.7%). The mean age at the time of diagnosis was 2.7 years with a median of 3 months. Thirty-nine (54.9%) children had karyotype testing done. The median age (IQR) of children with reported karyotypes and those without was 3.3 years (1.3–8.9) and 8.3 years (3.6–12.1), respectively (p=0.021). Based on karyotype analysis, 19 (48.7%) of karyotyped children had 46,XY DSD and 18 (46.2%) had 46,XX DSD. There were two (5.1%) children with sex chromosome DSD. Among the 71 patients, the most common presumed causes of DSD were ovotesticular DSD (14.1%) and CAH (11.3%). Majority (95.7%) of the patients presented with symptoms of DSD at birth. The most common presenting symptom was ambiguous genitalia, which was present in 66 (93.0%) patients either in isolation or in association with other symptoms. An ambiguous genitalia was initially observed by the patient’s mother in 51.6% of 62 cases despite the high rate (84.7%) of delivery in hospital. Seventeen (23.9%) of the cases had a gender reassignment at final diagnosis. A psychologist/psychiatrist or counselor was involved in the management of 23.9% of the patients. Conclusion. The commonest presumed cause of DSD was ovotesticular DSD in contrast to western studies, which found CAH to be more common. Investigation of DSD cases is expensive and needs to be supported. We would have liked to do molecular genetic analysis outside the country but financial challenges made it impossible. A network for detailed diagnostics in resource-limited countries would be highly desirable. There is a need to train health care workers and medical students for early diagnosis. Psychological evaluation should be carried out for all patients at diagnosis and support given for families.


2018 ◽  
Vol 7 (4) ◽  
pp. 595-603 ◽  
Author(s):  
E Kohva ◽  
P J Miettinen ◽  
S Taskinen ◽  
M Hero ◽  
A Tarkkanen ◽  
...  

Background We describe the phenotypic spectrum and timing of diagnosis and management in a large series of patients with disorders of sexual development (DSD) treated in a single pediatric tertiary center. Methods DSD patients who had visited our tertiary center during the survey period (between 2004 and 2014) were identified based on an ICD-10 inquiry, and their phenotypic and molecular genetic findings were recorded from patient charts. Results Among the 550 DSD patients, 53.3% had 46,XY DSD; 37.1% had sex chromosome DSD and 9.6% had 46,XX DSD. The most common diagnoses were Turner syndrome (19.8%, diagnosed at the mean age of 4.7 ± 5.5 years), Klinefelter syndrome (14.5%, 6.8 ± 6.2 years) and bilateral cryptorchidism (23.1%). Very few patients with 46,XY DSD (7%) or 46,XX DSD (21%) had molecular genetic diagnosis. The yearly rate of DSD diagnoses remained stable over the survey period. After the release of the Nordic consensus on the management of undescended testes, the age at surgery for bilateral cryptorchidism declined significantly (P < 0.001). Conclusions Our results show that (i) Turner syndrome and Klinefelter syndrome, the most frequent single DSD diagnoses, are still diagnosed relatively late; (ii) a temporal shift was observed in the management of bilateral cryptorchidism, which may favorably influence patients’ adulthood semen quality and (iii) next-generation sequencing methods are not fully employed in the diagnostics of DSD patients.


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