Anterior segment dysgenesis correlation with epithelial-mesenchymal transition in Smad4 knockout mice

AIM： To explore the molecular mechanisms in lens development and the pathogenesis of Peters anomaly in Smad4 defective mice. METHODS： Le-Cre transgenic mouse line was employed to inactivate Smad4 in the surface ectoderm selectively. Pathological techniques were used to reveal the morphological changes of the anterior segment in Smad4 defective eye. Immunohistochemical staining was employed to observe the expression of E-cadherin, N- cadherin and α-SMA in anterior segment of Smad4 defective mice and control mice at embryonic （E） day 16.5. Real-time quantitative polymerase chain reaction （qPCR） was performed to detect the expression of Snail, Zebl, Zeb2 and Twist2 in lens of Smad4 defective mice and control mice at E16.5. RESULTS： Conditional deletion of Smad4 on eye surface ectoderm resulted in corneal dysplasia, iridocorneal angle closure, corneolenticular adhesions and cataract resembling Peters anomaly. Loss of Smad4 function inhibited E-cadherin expression in the lens epithelium cells and corneal epithelium cells in Smad4 defective eye. Expression of N-cadherin was upregulated in corneal epithelium and corneal stroma. Both E-cadherin and N-cadherin were down-regulated at the future trabecular meshwork region in mutant eye. The qPCR results showed that the expression of Twist2 was increased significantly in the mutant lens （P〈0.01）. CONCLUSION： Smad4 is essential to eye development and likely a candidate pathogenic gene to Peters anomaly by regulating epithelial-mesenchymal transition. Twist2 can be regulated by Smad4 and plays an essential role in lens development.

A rare diagnosis:testicular dysgenesis with carcinoma in situ detected in a patient with ultrasonic microlithiasis

A rare case is presented where a dysgenetic testis with microinvasive carcinoma in situ （CIS, also known as intratubular germ cell neoplasm of unclassified type [IGCNU] and testicular intraepithelial neoplasia [TIN]） with microinvasion to rete testis and the interstitial tissue was found in a 32-year-old man presenting with mild scrotal pain and ultrasonic testicular microlithiasis. Knowledge of the association of ultrasound and CIS is important to diagnose patients at the stage prior to development of an overt germ cell tumor. The patient had three of four disorders considered symptoms of the testicular dysgenesis syndrome （TDS）： a dysgenetic left testicle with CIS, a mild left-sided cryptorchidism （high positioned scrotal hypotrophic testis） and a slightly reduced semen quality. Therefore, it should be kept in mind that a patient with one TDS symptom may harbour the other, even CIS or testicular cancer. Accordingly, patients with one TDS symptom ought to be examined for the presence of the others, and if more that one is present, extra concern is warranted.

Gonadal dysgenesis in Turner syndrome with Y-chromosome mosaicism:Two case reports

BACKGROUND Turner syndrome(TS)has a variety of different karyotypes,with a wide range of phenotypic features,but the specific karyotype may not always predict the phenotype.TS with Y chromosome mosaicism may have mixed gonadal dysgenesis,and the mosaicism is related to the potential for gonadoblastoma.CASE SUMMARY In this case report,we report two cases of TS with different karyotypes and gonadal dysgenesis.Patient 1 had obvious virilization,and was positive for the SRY gene,but her karyotype in peripheral blood lymphocytes was 45X.Patient 2 had a mosaic karyotype,45X/46X,dic(Y:Y)(p11.3:p11.2),and the proportion of Y-bearing cells was 50%in peripheral blood lymphocytes,but the patient had normal female external genitalia and streaky gonads,with no genital virilism.Different tissues in the same TS individual may exhibit different ratios of mosaicism.The gonadal determination and differentiation of mosaic TS are primarily dependent on the predominant cell line in the gonads.CONCLUSION In TS patients with virilization,it is necessary to test at least two to three tissues to search for cryptic Y material.

A FAMILIAL 46 XY GONADAL DYSGENESIS AND HIGH INCIDENCE OF EMBRYONIC GONADAL TUMORS

The Swyer’s syndrome, 46XY gonadal dysgenesis ( 46XYGD) or XY female, belongs to the category of sexual abnomality. The syndrome is characterized by a female phenotype with streak gonads, 46XY karyotype and complicated by frequent develop of gonadal tumors. A congragated familial 46XYGD was analyzed. We have examined the whole family from many aspects and have followed the affected members more than 10 years. In present case , all eight siblings phenotypically were girls ; the two eldest members died between 1970 1972 from embryonic gonadal tumors. Five of remaining 6 girls were affected by the syndrome of 46 XYGD and two have got the same kind of tumor dysgerminoma. By cytogenetic and cytobiological studies and on the basis of accumulated data the mechanism of gonadal carcinogenesis was analyzed. The origin of dysgerminoma for 46XYGD syndrome was postulated.

Genes associated with testicular germ cell tumors and testicular dysgenesis in patients with testicular microlithiasis

Testicular microlithiasis （TM） is one of the symptoms of testicular dysgenesis syndrome （TDS）. TM is particularly interesting as an informative marker of testicular germ cell tumors （TGCTs）. KIT ligand gene （KITLG）, BCL2 antagonist/killer 1 （BAK1）, and sprouty RTK signaling antagonist 4 （SPRY4） genes are associated with a high risk of TGCTs, whereas bone morphogenetic protein 7 gene （BMP7）, transforming growth factor beta receptor 3 gene （TGFBR3）, and homeobox D cluster genes （HOXD） are related to TDS. Using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） analysis, we investigated allele and genotype frequencies for KITLG （rs995030, rs1508595）, SPRY4 （rs4624820, rs6897876）, BAK1 （rs210138）, BMP7 （rs388286）, TGFBR3 （rs12082710）, and HOXD （rs17198432） in 142 TGCT patients, 137 TM patients, and 153 fertile men （control group）. We found significant differences in the KITLG GG_rs995030 genotype in TM （P= 0.01） and TGCT patients （P = 0.0005） compared with the control. We also revealed strong associations between KITLGrs1508595 and TM （G allele, P = 0.003; GG genotype, P= 0.01） and between KITLG_rs1508595 and TGCTs （G allele, P-- 0.0001; GG genotype, P = 0.0007）. Moreover, there was a significant difference in BMP7_rs388286 between the TGCT group and the control （T allele, P = 0.00004; TT genotype, P = 0.00006） and between the TM group and the control （T allele, P= 0.04）. HOXDalso demonstrated a strong association with TGCTs （rs17198432 A allele, P = 0.0001; AA genotype, P = 0.001）. Furthermore, significant differences were found between the TGCT group and the control in the BAK1_rs210138 G allele （P= 0.03） and the GG genotype （P= 0.01）. KITLG and BMP7genes, associated with the development of TGCTs, may also be related to TM. In summary, the KITLG GG_rs995030, GG_rs1508595, BMP7 TT_rs388286, HOXD AA_rs17198432, and BAK1 GG_rs210138 genotypes were associated with a high risk of TGCT development.

Thyroid dysfunction and developmental anomalies in first degree relatives of children with thyroid dysgenesis

Background: Familial clustering in patients withpermanent congenital hypothyroidism (CH) caused bythyroid dysgenesis (TD) has been reported in developedcountries. There is no information on familial TD fromdeveloping countries.Methods: A total of 312 first degree relativesbelonging to 80 families of children with TD (group 1)and 40 families of age-matched normal children (group2) were screened by thyroid ultrasonography, serum totalthyroxine (T4) and thyroid stimulating hormone (TSH).Results: Thyroid scintigraphy revealed agenesis in78.7% of the patients, ectopic gland in 15%, and hypoplasiain 6.2%. The mean thyroid volumes were similar in parentsand siblings of both groups. Eight (10.6%) mothers in group1 were identified to have thyroid hypoplasia as comparedwith none in group 2 (P=0.03). Serum TSH was signifi cantlyhigher in group 1 than in group 2 (P=0.004). Sixteen (7.8%)subjects (6 mothers, 5 fathers, and 5 siblings) in group 1were found to have subclinical hypothyroidism as comparedto none in group 2 (P<0.05). Four families were identifiedto have thyroid developmental anomalies and abnormalthyroid functions accounting for 5% of cases of familial TDin our cohort.Conclusions: Thyroid developmental anomalies andthyroid function abnormalities are more frequent in firstdegree relatives of children with TD as compared with acontrol population. These findings suggest that possiblythere is a genetic component of TD in Indian patients.

Case Report: Clinical and Diagnostic Aspects of Mayer-Rokitansky-Kuster-Hauser Syndrome

Mayer-Rokitansky-Kuster-Hauser Syndrome (MRKH) is a rare disease characterized by total or partial vagina agenesis, karyotype 46, XX with normal secondary sexual characters. Still, it is the second leading cause of primary amenorrhea. The absence of obvious signs and symptoms often causes the syndrome to be diagnosed only after puberty. The case presented here highlights exactly this difficulty of early diagnosis, which meets the objective of the study, and is precisely to provide reliable material that facilitates the diagnosis and management of patients with MRKH syndrome.

Laparoscopic Hemi-Hysterectomy-Retrospective Study of Case Series of over 9 Years

Background: Word hemi-hysterectomy and removal of rudimentary functional horn may be used interchangeably in published data. The same term may be used when a non-obstructive hemi-uterus is removed when there is an associated pathology. The article tries to standardise classification of Mullerian dysgenesis where this procedure is required according to ESHRE ESGE classification, preoperative diagnosis and discuss the operative details. Objective: The objective was to study the demographic profile, symptoms, association of endometriosis, variation in the anatomy, accuracy of preoperative diagnosis, to classify according to ESHRE ESGE classification and to standardize the laparoscopic surgical steps of hemi-hysterectomy. Study Design: This is a retrospective case series of cases of Mullerian dysgenesis with obstructive hemi-uterus or non-obstructive hemi-uterus with pathology treated by laparoscopic hemi-hysterectomy. (Canadian task force classification III). Methods: Data from hospital electronic records of all cases tagged with word laparoscopic hemi-hysterectomy were collected for 9 years from Jan 2009 to Dec 2018. Results: Total 19 patients of hemi-hysterectomy were analysed. Pre-operative diagnosis was made in 100% of patients. 100% patients with obstructive horn had dysmenorrhoea. ESHRE ESGE class U4aC3V0 was more frequently seen followed by U5aC4V4 and U3bC3V2 as obstructive and U4bC3V0, as non-obstructive. Associated endometriosis along with other pathology was seen in 74% of the patients. 3 patients with HWWS had ipsilateral renal agenesis. Laparoscopic hemi-hysterectomy was offered to all such patients. The operative steps & variants were studied. Post-operative outcome was uneventful in all. Conclusion: An experienced surgeon should deal with these problems of Mullerian dysgenesis discussed in this study. The other variants diagnosed also must be treated by an experienced surgeon only. Laparoscopic hemi-hysterectomy is almost the most standard surgical method to treat pelvic pain in cases with rudimentary non-communicating horns or in cases of non-obstructive horns with other associated pathologies. Post-operative recovery is uneventful, and all patients reported pain free periods as well as they are free of chronic pain which they had before surgery.

Evaluation and management of the child with hypothyroidism

Background Thyroid hormones are critical for early neurocognitive development as well as growth and development throughout childhood.Prompt recognition and treatment of hypothyroidism is,therefore,of utmost importance to optimize physical and neurodevelopmental outcomes.Data sources A PubMed search was completed in Clinical Queries using the key terms 'hypothyroidism'.Results Hypothyroidism may be present at birth (congenital hypothyroidism) or develop later in life (acquired hypothyroidism).Thyroid dysgenesis and dyshormonogenesis account for approximately 85% and 15% of permanent cases of congenital primary hypothyroidism,respectively.More than 95% of infants with congenital hypothyroidism have few,if any,clinical manifestations of hypothyroidism.Newborn screening programs allow early detection of congenital hypothyroidism.In developed countries,Hashimoto thyroiditis is the most common cause of goiter and acquired hypothyroidism in children and adolescents.Globally,iodine deficiency associated with goiter is the most common cause of hypothyroidism.Central hypothyroidism is uncommon and may be associated with other congenital syndromes and deficiencies of other pituitary hormones.Familiarity of the clinical features would allow prompt diagnosis and institution of treatment.Conclusions To optimize neurocognitive outcome in infants with congenital hypothyroidism,treatment with levothyroxine should be started as soon as possible,preferably within the first 2 weeks of life.Children with acquired hypothyroidism should also be treated early to ensure normal growth and development as well as cognitive outcome.The target is to keep serum TSH < 5 mIU/L and to maintain serum free T4 or total T4 within the upper half of the age-specific reference range,with elimination of all symptoms and signs of hypothyroidism.

Genetics of congenital hypothyroidism: Modern concepts

Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and one of the most common preventable causes of intellectual disability in the world. CH may be due to developmental or functional thyroid defects (primary or peripheral CH) or be hypothalamic-pituitary in origin (central CH). In most cases, primary CH is caused by a developmental malformation of the gland (thyroid dysgenesis, TD) or by a defect in thyroid hormones synthesis (dyshormonogenesis, DH). TD represents about 65% of CH and a genetic cause is currently identified in fewer than 5% of patients. The remaining 35% are cases of DH and are explained with certainty at the molecular level in more than 50% of cases. The etiology of CH is mostly unknown and may include contributions from individual and environmental factors. In recent years, the detailed phenotypic description of patients, high-throughput sequencing technologies, and the use of animal models have made it possible to discover new genes involved in the development or function of the thyroid gland. This paper reviews all the genetic causes of CH. The modes by which CH is transmitted will also be discussed, including a new oligogenic model. CH is no longer simply a dominant disease for cases of CH due to TD and recessive for cases of CH due to DH, but a far more complex disorder.

Silencing of Transposable Elements by piRNAs in Drosophila:An Evolutionary Perspective

Transposable elements （TEs） are DNA sequences that can move within the genome. TEs have greatly shaped the genomes, transcriptomes, and proteomes of the host organisms through a variety of mechanisms. However, TEs generally disrupt genes and destabilize the host genomes, which substantially reduce fitness of the host organisms. Understanding the genomic distribution and evolutionary dynamics of TEs will greatly deepen our understanding of the TE-mediated bio- logical processes. Most TE insertions are highly polymorphic in Drosophila melanogaster, providing us a good system to investigate the evolution of TEs at the population level. Decades of theoretical and experimental studies have well established ＂transposition-selection＂ population genetics model, which assumes that the equilibrium between TE replication and purifying selection determines the copy number of TEs in the genome. In the last decade, P-element-induced wimpy testis （PIW1）- interacting RNAs （piRNAs） were demonstrated to be master repressors of TE activities in Droso- phila, The discovery of piRNAs revolutionized our understanding of TE repression, because it reveals that the host organisms have evolved an adaptive mechanism to defend against TE invasion. Tremendous progress has been made to understand the molecular mechanisms by which piRNAs repress active TEs, although many details in this process remain to be further explored. The inter- action between piRNAs and TEs well explains the molecular mechanisms underlying hybrid dysge- nesis for the IoR and P-M systems in Drosophila, which have puzzled evolutionary biologists for decades. The piRNA repression pathway provides us an unparalleled system to study the co-evolutionary process between parasites and host organisms.

Management of children with disorders of sex development:20-year experience in southern Thailand

Background:Disorders of sex development(DSD)is a group of sexual differentiation disorders resulting in genital anomalies with defects in gonadal hormone synthesis and/or incomplete genital development.These conditions result in problems concerning the sex assignment of the child.This study aims to describe the clinical features,diagnosis and management of children with DSD in southern Thailand.Methods:The medical records of 117 pediatric patients diagnosed with DSD during the period of 1991-2011 were retrospectively reviewed.Results:Disorders of sex development were categorized into 3 groups:sex chromosome abnormalities(53.0%),46,XX DSD(29.9%)and 46,XY DSD(17.1%).The two most common etiologies of DSD were Turner syndrome(36.8%)and congenital adrenal hyperplasia(29.9%).Ambiguous genitalia/intersex was the main problem in 46,XX DSD(94%)and 46,XY DSD(100%).Sex reassignment was done in 5 children(4.3%)at age of 3-5 years:from male to female in 4 children(1 patient with congenital adrenal hyperplasia,1 patient with 45,X/46,XY DSD,and 2 patients with 46,XX ovotesticular DSD)and from female to male in 1 patient with 46,XX ovotesticular DSD.Of the total 20 children with 46,XY DSD,16(80%)were raised as females.Conclusion:Management of DSD children has many aspects of concern.Sex assignment/reassignment depends on the phenotype(phallus size)of the external genitalia rather than the sex chromosome.

Twin dilivery of a 46,XY gonadal dysgenetic woman following vitrified oocytes donation

A 46,XY gonadal dysgenetic woman gave birth to two healthy girls following vitrified oocytes donation. The loss of SRY gene was considered as the cause of this patient. Although similar cases have been reported about pregnancies of 46,XY pure gonadal dysgenetic women, successful delivery from vitrified oocytes has been hardly reported yet. Oocytes vitrification technique provides a beneficial way by saving superfluous oocytes from the pregnancy patients to these women who need.

A novel mutation in the SRY gene of a Chinese 46,XY female patient with unilateral mixed germ cell tumor

Objective To determine the nosogenetic factors of a 46,XY female with primary amenorrhea and unilateral mixed germ cell tumor.Methods Eight genes associated with 46,XY gonadal dysgenesis were detected in the patient and her parents by target region captured-next generation sequencing.Results An insertion of a single nucleotide（adenine） at the coding site 230（c.230231insA） located in the high mobility group（HMG） domain of SRY was revealed,which led to a truncated protein（p.Lys77 fsX 27）. This mutation was at position 2655414 of the Y chromosome, supported with 127 unique mapped reads, however, this mutation was not found in the in-house dataset of 1 092 controls. Additionally, none of the candidate gene was detected in the patient’s parents, which indicated that it is a de novo mutation.Conclusion A novel SRY sporadic mutation due to a single nucleotide insertion at position 230（c.230231insA） was identified as the cause of the disease in this patient.Target region captured-next generation sequencing was found to be an effective method for the molecular genetic testing of 46,XY complete gonadal dysgenesis（46,XY CGD）.