A Single-Center, Observational Study of 607 Children and Young People Presenting With Differences of Sex Development (DSD)

Context

Differences of sex development (DSD) represent a wide range of conditions presenting at different ages to various health professionals. Establishing a diagnosis, supporting the family, and developing a management plan are important.

Objective

We aimed to better understand the presentation and prevalence of pediatric DSD.

Methods

A retrospective, observational cohort study was undertaken in a single tertiary pediatric center of all children and young people (CYP) referred to a DSD multidisciplinary team over 25 years (1995-2019). In total, 607 CYP (520 regional referrals) were included. Data were analyzed for diagnosis, sex-assignment, age and mode of presentation, additional phenotypic features, mortality, and approximate point prevalence.

Results

Among the 3 major DSD categories, sex chromosome DSD was diagnosed in 11.2% (68/607) (most commonly 45,X/46,XY mosaicism), 46,XY DSD in 61.1% (371/607) (multiple diagnoses often with associated features), while 46,XX DSD occurred in 27.7% (168/607) (often 21-hydroxylase deficiency). Most children (80.1%) presented as neonates, usually with atypical genitalia, adrenal insufficiency, undescended testes or hernias. Those presenting later had diverse features. Rarely, the diagnosis was made antenatally (3.8%, n = 23) or following incidental karyotyping/family history (n = 14). Mortality was surprisingly high in 46,XY children, usually due to complex associated features (46,XY girls, 8.3%; 46,XY boys, 2.7%). The approximate point prevalence of neonatal referrals for investigation of DSD was 1 in 6347 births, and 1 in 5101 overall throughout childhood.

Conclusion

DSD represent a diverse range of conditions that can present at different ages. Pathways for expert diagnosis and management are important to optimize care.

Congenital infections in Hong Kong: beyond TORCH

Congenital infections refer to a group of perinatal infections that are caused by pathogens transmitted from mother to child during pregnancy (transplacentally) or delivery (peripartum) which may have similar clinical presentations, including rash and ocular findings. TORCH is the acronym that covers these infections (toxoplasmosis, other [syphilis], rubella, cytomegalovirus, herpes simplex virus). Other important causes of intrauterine/perinatal infection include human immunodeficiency virus, varicella-zoster virus, Treponema pallidum, Zika virus, and parvovirus B19. This overview aims to describe various congenital infections beyond TORCH with a Hong Kong perspective. Intrauterine and perinatal infections are a major cause of in utero death and neonatal mortality, and an important contributor to childhood morbidity. A high index of suspicion for congenital infections and awareness of the prominent features of the most common congenital infections can help to facilitate early diagnosis, tailor appropriate diagnostic evaluation, and initiate appropriate early treatment. Intrauterine infections should be suspected in newborns with clinical features including microcephaly, seizures, cataract, hearing loss, congenital heart disease, hepatosplenomegaly, small for gestational age, and/or rash. Primary prevention of maternal infections during pregnancy is key to the prevention of congenital infection, and resources (if available) should focus on public health promotion and pre-marital counselling.

Congenital infections in Hong Kong: an overview of TORCH

Congenital infections refer to a group of perinatal infections that may have similar clinical presentations, including rash and ocular findings. TORCH is the acronym that covers these infections (toxoplasmosis, other [syphilis], rubella, cytomegalovirus, herpes simplex virus). There are, however, other important causes of intrauterine/perinatal infections, including enteroviruses, varicella zoster virus, Zika virus, and parvovirus B19. Intrauterine and perinatal infections are significant causes of fetal and neonatal mortality and important contributors to childhood morbidity. A high index of suspicion for congenital infections and awareness of the prominent features of the most common congenital infections can help to facilitate early diagnosis, tailor appropriate diagnostic evaluation, and if appropriate, initiate early treatments. In the absence of maternal laboratory results diagnostic of intrauterine infections, congenital infections should be suspected in newborns with certain clinical features or combinations of clinical features, including hydrops fetalis, microcephaly, seizures, cataract, hearing loss, congenital heart disease, hepatosplenomegaly, jaundice, or rash. Primary prevention of maternal infections during pregnancy is the cornerstone of prevention of congenital infection. Available resources should focus on the promotion of public health.

Next-Generation Sequencing Reveals Novel Genetic Variants (SRY, DMRT1, NR5A1, DHH, DHX37) in Adults With 46,XY DSD

CONTEXT

The genetic basis of human sex development is slowly being elucidated, and >40 different genetic causes of differences (or disorders) of sex development (DSDs) have now been reported. However, reaching a specific diagnosis using traditional approaches can be difficult, especially in adults where limited biochemical data may be available.

OBJECTIVE

We used a targeted next-generation sequencing approach to analyze known and candidate genes for DSDs in individuals with no specific molecular diagnosis.

PARTICIPANTS AND DESIGN

We studied 52 adult 46,XY women attending a single-center adult service, who were part of a larger cohort of 400 individuals. Classic conditions such as17β-hydroxysteroid dehydrogenase deficiency type 3, 5α-reductase deficiency type 2, and androgen insensitivity syndrome were excluded. The study cohort had broad working diagnoses of complete gonadal dysgenesis (CGD) (n = 27) and partially virilized 46,XY DSD (pvDSD) (n = 25), a group that included partial gonadal dysgenesis and those with a broad "partial androgen insensitivity syndrome" label. Targeted sequencing of 180 genes was undertaken.

RESULTS

Overall, a likely genetic cause was found in 16 of 52 (30.8%) individuals (22.2% CGD, 40.0% pvDSD). Pathogenic variants were found in sex-determining region Y (SRY; n = 3), doublesex and mab-3-related transcription factor 1 (DMRT1; n = 1), NR5A1/steroidogenic factor-1 (SF-1) (n = 1), and desert hedgehog (DHH; n = 1) in the CGD group, and in NR5A1 (n = 5), DHH (n = 1), and DEAH-box helicase 37 (DHX37; n = 4) in the pvDSD group.

CONCLUSIONS

Reaching a specific diagnosis can have clinical implications and provides insight into the role of these proteins in sex development. Next-generation sequencing approaches are invaluable, especially in adult populations or where diagnostic biochemistry is not possible.

Associations between arterial structure and function and serum levels of liver enzymes in obese adolescents

AIM

To determine the structural and functional alterations of systemic arteries in obese adolescents and their relationships with adiposity, metabolic and lipid profile, and serum liver enzyme levels.

METHODS

Carotid intima-media thickness (IMT), carotid stiffness index, and brachial-ankle pulse wave velocity (baPWV) were measured in 56 obese adolescents and 58 lean controls. Obese adolescents had additional liver ultrasound and determination of fasting blood indices of glucose metabolism and lipid profile, and serum levels of liver enzymes.

RESULTS

Carotid IMT (P < 0.0001), carotid stiffness index (P < 0.0001) and baPWV (P = 0.001) were significantly greater in obese than control subjects. Thirty-seven (66%) obese subjects had fatty liver changes and their aspartate aminotransferase, alanine aminotransferase (ALT), alkaline phosphatase, and gamma-glutamyl transferase levels were significantly higher than those without (all P < 0.05). Univariate analyses showed positive correlations between serum ALT (r = 0.29, P = 0.03) and alkaline phosphatase (r = 0.28, P = 0.04) levels and carotid IMT, aspartate aminotransferase level and carotid stiffness (r = 0.41, P = 0.002), and gamma-glutamyl transferase level and baPWV (r = 0.34, P = 0.02) in obese subjects. Multivariate linear regression revealed serum ALT level (β = 0.02, P = 0.006) as an independent correlate of carotid stiffness.

CONCLUSION

Obese adolescents have increased carotid IMT and stiffness, which are associated positively with serum liver enzyme levels.

Myocardial Integrated Backscatter in Obese Adolescents: Associations with Measures of Adiposity and Left Ventricular Deformation

Background

Myocardial fibrosis has been proposed to play an important pathogenetic role in left ventricular (LV) dysfunction in obesity. This study tested the hypothesis that calibrated integrated backscatter (cIB) as a marker of myocardial fibrosis is altered in obese adolescents and explored its associations with adiposity, LV myocardial deformation, and metabolic parameters.

Methods/Principal Findings

Fifty-two obese adolescents and 38 non-obese controls were studied with conventional and speckle tracking echocardiography. The average cIB of ventricular septum and LV posterior wall was measured. In obese subjects, insulin resistance as estimated by homeostasis model assessment (HOMA-IR) and glucose tolerance were determined. Compared with controls, obese subjects had significantly greater cIB of ventricular septum (-16.8±7.8 dB vs -23.2±7.8 dB, p<0.001), LV posterior wall (-20.5±5.6 dBvs -25.0±5.1 dB, p<0.001) and their average (-18.7±5.7 dB vs -24.1±5.0 dB, p<0.001). For myocardial deformation, obese subjects had significantly reduced LV longitudinal systolic strain rate (SR) (p = 0.045) and early diastolic SR (p = 0.015), and LV circumferential systolic strain (p = 0.008), but greater LV longitudinal late diastolic SR (p<0.001), and radial early (p = 0.037) and late (p = 0.002) diastolic SR than controls. For the entire cohort, myocardial cIB correlated positively with body mass index (r = 0.45, p<0.001) and waist circumference (r = 0.45, p<0.001), but negatively with LV circumferential systolic strain (r = -0.23, p = 0.03) and systolic SR (r = -0.25, p = 0.016). Among obese subjects, cIB tended to correlate with HOMA-IR (r = 0.26, p = 0.07).

Conclusion

Obese adolescents already exhibit evidence of increased myocardial fibrosis, which is associated with measures of adiposity and impaired LV circumferential myocardial deformation.

NGS identifies TAZ mutation in a family with X-linked dilated cardiomyopathy

We reported a family with two male siblings affected with infantile dilated cardiomyopathy (DCM). Extensive evaluation failed to identify the underlying cause for the DCM. Next generation sequencing (NGS) with targeted enrichment identified a hemizygous variant c.718G>C (p.Gly240Arg) in the TAZ gene. This variant has been reported in three other families with X linked infantile DCM and is therefore likely pathogenic. NGS allows efficient screening of a large number of uncommon genes in complex disorders like DCM, in which there is substantial genetic and phenotypic heterogeneity. The identification of TAZ mutation has major impact on their medical care as the surveillance needs to be expanded to cover for the Barth syndrome, a severe metabolic phenotype also caused by TAZ mutation, in addition to DCM.