Dermatological concerns for women and girls with turner syndrome

Introduction

Turner syndrome (TS) is associated with distinct manifestations in women and girls including short stature, cardiac abnormalities, premature ovarian failure as well as dermatological features, including lymphedema, keloids, onychodystrophy, and acne. Although many dermatological concerns present during the first few decades of life, the overwhelming majority of respondents are not provided with dermatology referrals at diagnosis.

Methods

This cross-sectional study utilized an author designed survey to assess self-reported dermatological manifestations, dermatology referral experience, common therapies for select dermatological conditions, as well as a validated 10-question Dermatology Life Quality Index (DLQI) to assess quality-of-life impact in women and girls with Turner syndrome.

Results

In our cohort, 64% (n = 149) had been referred to a dermatologist at some point in their life time. The majority of individuals self-identified their dermatological concern (79.6%) and were referred after a dermatological concern had already occurred (90.2%). The most common dermatological findings reported were xerosis cutis (78.7%), lymphedema (73%), and more than 20 acquired melanocytic nevi (70%). The overall mean DLQI score was 3.52, indicative of a small effect on the patient's life. Onychodystrophy, history of skin biopsy, and lymphedema were statistically significant to have a higher impact on quality of life.

Discussion

Our data reveal that skin conditions are highly prevalent in the TS population during the early decades of life and affirm utilizing these conditions in the TS diagnostic process, as well as emphasize the need for specialized dermatology referrals to address the detrimental impacts related to skin concerns on quality of life.

A Prospective Study on Continuous Glucose Monitoring in Glycogen Storage Disease Type Ia: Toward Glycemic Targets

CONTEXT

Although previous research has shown the benefit of continuous glucose monitoring (CGM) for hepatic glycogen storage diseases (GSDs), current lack of prospectively collected CGM metrics and glycemic targets for CGM-derived outcomes in the hepatic GSD population limits its use.

OBJECTIVE

To assess CGM metrics for glycemic variation and glycemic control in adult patients with GSDIa as compared to matched healthy volunteers.

DESIGN

Prospective CGM data were collected during the ENGLUPRO GSDIa trial (NCT04311307) in which a Dexcom G6 device was used. Ten adult patients with GSDIa and 10 age-, sex- and body mass index-matched healthy volunteers were enrolled. Capillary blood glucose was concurrently measured during 2 standardized 2-hour time intervals. Descriptive [eg, glycemic variability (GV), time below range, time in range (TIR), time above range (TAR)] and advanced (ie, first- and second-order derivatives, Fourier analysis) CGM outcomes were calculated. For each descriptive CGM outcome measure, 95% CIs were computed in patients with GSDIa and healthy volunteers, respectively.

RESULTS

CGM overestimation was higher under preprandial and level 1 hypoglycemia (ie, capillary glucose values ≥ 3.0 mmol/L and < 3.9 mmol/L) conditions. GV and TAR were higher while TIR was lower in patients with GSDIa compared to healthy volunteers (P < 0.05). Three patients with GSDIa showed descriptive CGM outcomes outside the calculated 95% CI in GSDIa patients. Advanced CGM analysis revealed a distinct pattern (ie, first- and second-order derivatives and glucose curve amplitude) in each of these 3 patients within the patients group.

CONCLUSIONS

This is the first study to prospectively compare CGM outcomes between adult patients with GSDIa and matched healthy volunteers. The generation of a set of CGM metrics will provide guidance in using and interpreting CGM data in GSDIa and will be useful for the definition of glycemic targets for CGM in patients with GSDIa. Future studies should investigate the prognostic value of CGM outcomes and their major determinants in patients with GSDIa.

Human KCNQ5 de novo mutations underlie epilepsy and intellectual disability

We identified six novel de novo human KCNQ5 variants in children with motor/language delay, intellectual disability (ID), and/or epilepsy by whole exome sequencing. These variants, comprising two nonsense and four missense alterations, were functionally characterized by electrophysiology in HEK293/CHO cells, together with four previously reported KCNQ5 missense variants (Lehman A, Thouta S, Mancini GM, Naidu S, van Slegtenhorst M, McWalter K, Person R, Mwenifumbo J, Salvarinova R; CAUSES Study; EPGEN Study; Guella I, McKenzie MB, Datta A, Connolly MB, Kalkhoran SM, Poburko D, Friedman JM, Farrer MJ, Demos M, Desai S, Claydon T. Am J Hum Genet 101: 65-74, 2017). Surprisingly, all eight missense variants resulted in gain of function (GOF) due to hyperpolarized voltage dependence of activation or slowed deactivation kinetics, whereas the two nonsense variants were confirmed to be loss of function (LOF). One severe GOF allele (P369T) was tested and found to extend a dominant GOF effect to heteromeric KCNQ5/3 channels. Clinical presentations were associated with altered KCNQ5 channel gating: milder presentations with LOF or smaller GOF shifts in voltage dependence [change in voltage at half-maximal conduction (ΔV₅₀) = ∼-15 mV] and severe presentations with larger GOF shifts in voltage dependence (ΔV₅₀ = ∼-30 mV). To examine LOF pathogenicity, two Kcnq5 LOF mouse lines were created with CRISPR/Cas9. Both lines exhibited handling- and thermal-induced seizures and abnormal cortical EEGs consistent with epileptiform activity. Our study thus provides evidence for in vivo KCNQ5 LOF pathogenicity and strengthens the contribution of both LOF and GOF mutations to global pediatric neurological impairment, including ID/epilepsy.NEW & NOTEWORTHY Six novel de novo human KCNQ5 variants were identified from children with neurodevelopmental delay, intellectual disability, and/or epilepsy. Expression of these variants along with four previously reported KCNQ5 variants from a similar cohort revealed GOF potassium channels, negatively shifted in V₅₀ of activation and/or delayed deactivation kinetics. GOF is extended to KCNQ5/3 heteromeric channels, making these the predominant channels affected in heterozygous de novo patients. Kcnq5 LOF mice exhibited seizures, consistent with in vivo pathogenicity.

Expanding Our Knowledge of Menstrual Irregularities Reported by Females With Tuberous Sclerosis Complex

Purpose

The purpose of our study is to expand the knowledge regarding intrinsic reproductive dysfunction in females with TSC and to explore the impact of mTOR inhibitors (mTORi) on menstrual irregularity in the Tuberous Sclerosis Complex (TSC) community.

Methods

An electronic survey composed of author-designed questions set out to evaluate reproductive history, presence of menstrual irregularities, mTORi use, as well as maternal reproductive history among females with TSC.

Results

Of the 68 responses from females with TSC regarding age of menarche, the average age was 12.3 years. 56.5% (n = 48) of respondents reported irregular menstrual cycles and noted a total of 102 menstrual irregularities. There was a cohort of 35 women with a reported history of mTORi use. Of these women, 68.6% (n = 24) reported irregular menstrual cycles after taking mTORi. In comparison, among the females with no history of mTORi use (n = 50) only 48% reported irregular menstrual cycles (n = 24).

Conclusions

Our data expands the knowledge regarding intrinsic menstrual dysregulation present in women with TSC, demonstrates a rate of menstrual irregularities among females taking mTORi, and identifies a tendency toward early menarche that may be a previously unrecognized feature of TSC.

Otolaryngology Utilization in Patients With Achondroplasia: Results From the CLARITY Study

OBJECTIVES/HYPOTHESIS

To quantify otolaryngologic surgery utilization in patients with achondroplasia, and to identify any changes in utilization over the past four decades.

STUDY DESIGN

Retrospective cohort study.

METHODS

A retrospective cohort study of 1,374 patients with achondroplasia enrolled in the CLARITY retrospective cohort study at four centers of multi-specialty care for patients with achondroplasia. Otolaryngologic surgeries are presented by birth cohort decade. The main outcomes were number of primary and additional otolaryngologic procedures; age at surgery; likelihood of repeated surgery; temporal trends in surgical utilization.

RESULTS

In this cohort of 1,374 patients with achondroplasia, 620 (45.1%) had pharyngeal surgery at least once, 150 (10.9%) had pharyngeal surgery on more than one occasion, and patients who had adenoidectomy first were 2.68 times more likely to require a second pharyngeal surgery than those who had adenotonsillectomy. Seven hundred and seventy-nine (56.7%) had tympanostomy tubes placed at least once, and 447 (32.5%) had tympanostomy tubes placed more than one time. Age at first pharyngeal surgery decreased by 1.2 years per birth cohort decade, and age at tympanostomy tube placement decreased by 1.1 years per decade.

CONCLUSIONS

Patients with achondroplasia often require otolaryngologic surgery, particularly adenoidectomy and/or tonsillectomy as well as tympanostomy tube placement. Such surgery is performed now more frequently and at younger ages than in earlier decades. While otolaryngologic disease associated with achondroplasia is now recognized earlier and treated more frequently, long-term outcome studies are needed.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Congenital heart defects and copy number variants associated with neurodevelopmental impairment

A genetic etiology is identifiable in 20%-30% of patients with congenital heart defects (CHD). Chromosomal microarray analysis (CMA) can detect copy number variants (CNV) associated with CHD. In previous studies, the diagnostic yield of postnatal CMA testing ranged from 4% to 28% in CHD patients. However, incidental pathogenic CNV and variants of unknown significance are often discovered without any known association with CHD. The study objective was to describe the rate of pathogenic CNV associated with neurodevelopmental impairment (NDI) and compare clinical findings in CHD neonates with genetic results. A single-center retrospective review was performed on all consecutive newborns with CHD admitted to a tertiary neonatal intensive care unit from January 2013 to March 2019 (n = 525). CHD phenotypes were classified as per the National Birth Defect Prevention Study. CMA detected pathogenic CNV in 21.3% (61/287) of neonates, and karyotype or fluorescence in situ hybridization detected aneuploidies in an additional 11% of the overall cohort (58/525). Atrioventricular septal defects and conotruncal defects showed the highest diagnostic yield by CMA (28.6% and 27.2%, respectively). Among neonates with pathogenic CNV on CMA, 78.7% (48/61) were associated with NDI. Neonates with pathogenic CNV were smaller in length at birth compared to those with benign CNV or variants of unknown significance (p = 0.005) and were more likely to be discharged with an enteral feeding tube (p = 0.027). CMA can discover genetic variants associated with NDI and are common in neonates with CHD. Genetic testing in the neonatal period can heighten awareness of genetic risk for NDI.

Frequency, Progression, and Current Management: Report of 16 New Cases of Nonfunctional Pancreatic Neuroendocrine Tumors in Tuberous Sclerosis Complex and Comparison With Previous Reports

Background: Tuberous sclerosis complex (TSC) is a genetic condition that causes benign tumors to grow in multiple organ systems. Nonfunctional pancreatic neuroendocrine tumors (PNETs) are a rare clinical feature of TSC with no specific guidelines outlined for clinical management at this time. Our purpose is to calculate the frequency of nonfunctional PNETs as well as characterize the presentation, current clinical management, and assess the impact of systemic mammalian target of rapamycin (mTOR) on nonfunctional PNETs in TSC.

Methods: This retrospective chart review was performed by a query of the TS Alliance's Natural History Database and the Cincinnati Children's Hospital TSC Database for patients with nonfunctional PNET. Clinical data from these two groups was summarized for patients identified to have a nonfunctional PNET and compared to previously reported cases with TSC and nonfunctional PNETs.

Results: Our calculated frequency of nonfunctional PNETs is 0.65%. We identified 16 individuals, nine males and seven females, with a median age of 18.0 years (interquartile range: −15.5 to 25.5). Just over half (56.3%, n = 9) of the patients provided results from genetic testing. Six had pathogenic variants in TSC2 whereas three had pathogenic variants in TSC1. The average age at PNET diagnosis was 15.0 years (range: 3–46 years). Almost all individuals were diagnosed with a PNET during routine TSC surveillance, 56.3% (n = 9) by MRI, 12.5% (n = 2) by CT, 25% (n = 4) by ultrasound, and 6.2% (n = 1) through a surgical procedure. Follow up after diagnosis involved 68.8% (n = 11) having serial imaging and nine of the sixteen individuals proceeding with surgical removal of the PNET. Eight individuals had a history of using systemic mTOR inhibitors. Tumor growth rate was slightly less in individuals taking an mTOR inhibitor (−0.8 mm/yr, IQR: −2.3 to 2.2) than those without (1.6 mm/yr; IQR: −0.99 to 5.01, p > 0.05).

Conclusions: Nonfunctional PNETs occurred at younger ages in our TSC cohort and more commonly compared to ages and prevalence reported for the general population. PNETs in patients on systemic mTOR inhibitors had lower rates of growth. The outcome of this study provides preliminary evidence supporting the use of mTOR inhibitor therapy in conjunction with serial imaging as medical management for nonfunctional PNETs as an alternative option to invasive surgical removal.

Hypoglycemia in mitochondrial disorders

Diabetes and hyperglycemia are common features of mitochondrial disorders. This study investigates the frequency of non-iatrogenic hypoglycemia in individuals with these disorders. Of 116 patients, 22 (18.97%) experienced at least two episodes of hypoglycemia. This rate is significantly higher (p < 0.05) than the 6% seen in the non-diabetic, general population. Neonatal readings were 30 mg/dL lower than non-neonatal readings. As hypoglycemia appears to occur frequently in individuals with mitochondrial disorders, with lower blood glucose levels in the neonatal period, early and continued monitoring of blood glucose is necessary. Also, mitochondrial disorders should be considered in cases of recurrent hypoglycemia.

DYRK1A-related intellectual disability: a syndrome associated with congenital anomalies of the kidney and urinary tract

PURPOSE

Haploinsufficiency of DYRK1A causes a recognizable clinical syndrome. The goal of this paper is to investigate congenital anomalies of the kidney and urinary tract (CAKUT) and genital defects (GD) in patients with DYRK1A variants.

METHODS

A large database of clinical exome sequencing (ES) was queried for de novo DYRK1A variants and CAKUT/GD phenotypes were characterized. Xenopus laevis (frog) was chosen as a model organism to assess Dyrk1a's role in renal development.

RESULTS

Phenotypic details and variants of 19 patients were compiled after an initial observation that one patient with a de novo pathogenic variant in DYRK1A had GD. CAKUT/GD data were available from 15 patients, 11 of whom presented with CAKUT/GD. Studies in Xenopus embryos demonstrated that knockdown of Dyrk1a, which is expressed in forming nephrons, disrupts the development of segments of embryonic nephrons, which ultimately give rise to the entire genitourinary (GU) tract. These defects could be rescued by coinjecting wild-type human DYRK1A RNA, but not with DYRK1AR205* or DYRK1AL245R RNA.

CONCLUSION

Evidence supports routine GU screening of all individuals with de novo DYRK1A pathogenic variants to ensure optimized clinical management. Collectively, the reported clinical data and loss-of-function studies in Xenopus substantiate a novel role for DYRK1A in GU development.

Current genetic counseling practice in the United States following positive non-invasive prenatal testing for sex chromosome abnormalities

The purpose of this study was to describe current genetic counseling practice in the United States following a non-invasive prenatal testing (NIPT) result positive for a sex chromosome abnormality (SCA). Screening for SCAs can be confounded by confined placental mosaicism, natural loss of the X chromosome from maternal cells during aging, and undiagnosed maternal SCA or copy number variant (CNV). Furthermore, with the exception of 45,X, individuals with SCAs usually have no ultrasound or postnatal findings. This makes follow-up for unresolved positive NIPT necessary; however, there are currently no clinical guidelines. This study used a cross-sectional design with an anonymous questionnaire to survey 176 genetic counselors. The majority of prenatal respondents always offered diagnostic testing (>88%) and anatomy ultrasound (~90%), but the percent consistently offering maternal karyotype (22%-52%) and postnatal evaluation (28%-87%) varied. Maternal karyotype was offered more often when NIPT was positive for 45,X or 47,XXX and patients had normal prenatal diagnostic testing (p < 0.02) or declined testing (p < 0.02). Offer of postnatal evaluation was more likely when diagnostic testing was declined (p < 0.001). The majority of pediatric providers always offered a postnatal karyotype for the newborn (>72%) but the percent offering maternal karyotype (6%-46%) varied widely. With the current inconsistencies, many newborns with undiagnosed SCAs who could benefit from growth hormone therapy, early intervention, and/or targeted surveillance may be missed. Therefore, there is a need for professional guidelines to help improve the consistency of clinical care for patients with NIPT results positive for SCAs.

The utilization of prenatal microarray: A survey of current genetic counseling practices and barriers

OBJECTIVE

We evaluated what prenatal genetic counselor's (GCs) practices, attitudes, and barriers are in regards to prenatal microarray since the publication of the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) guidelines for microarray use.

METHODS

This was a survey-based cross-sectional study of English-speaking, board certified or eligible GCs who currently practice prenatal genetic counseling.

RESULTS

Of 192 respondents, 183 (95%) have incorporated chromosome microarray (CMA) into clinical practice, with 64% believing that the benefits of CMA outweigh the harms and 52% agreeing that CMA should be offered to all women regardless of indication. Those who reported being experts/comfortable in their knowledge of CMA (85%) and familiar with current clinical guidelines (86%) were significantly more likely to offer CMA to patients undergoing invasive testing and patients with fetal anomalies. Patient-specific concerns were the largest reported barrier (51%) when GCs do not offer CMA to patients.

CONCLUSION

Our study demonstrates GCs follow guidelines for CMA use when specific indications are involved, but further guidelines are needed regarding CMA use for other routine indications where utility of CMA is not clearly understood. On this basis, ACOG and SMFM should continue revising their guidelines as more information comes to light regarding utility of prenatal CMA for all indications, and organizations like the National Society of Genetic Counselors (NSGC) should consider publishing guidelines on prenatal CMA that are specialized to the GCs sphere of practice.

Loss of Function of the Nuclear Receptor NR2F2, Encoding COUP-TF2, Causes Testis Development and Cardiac Defects in 46,XX Children

Emerging evidence from murine studies suggests that mammalian sex determination is the outcome of an imbalance between mutually antagonistic male and female regulatory networks that canalize development down one pathway while actively repressing the other. However, in contrast to testis formation, the gene regulatory pathways governing mammalian ovary development have remained elusive. We performed exome or Sanger sequencing on 79 46,XX SRY-negative individuals with either unexplained virilization or with testicular/ovotesticular disorders/differences of sex development (TDSD/OTDSD). We identified heterozygous frameshift mutations in NR2F2, encoding COUP-TF2, in three children. One carried a c.103_109delGGCGCCC (p.Gly35Argfs^∗75) mutation, while two others carried a c.97_103delCCGCCCG (p.Pro33Alafs^∗77) mutation. In two of three children the mutation was de novo. All three children presented with congenital heart disease (CHD), one child with congenital diaphragmatic hernia (CDH), and two children with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). The three children had androgen production, virilization of external genitalia, and biochemical or histological evidence of testicular tissue. We demonstrate a highly significant association between the NR2F2 loss-of-function mutations and this syndromic form of DSD (p = 2.44 × 10⁻⁸). We show that COUP-TF2 is highly abundant in a FOXL2-negative stromal cell population of the fetal human ovary. In contrast to the mouse, these data establish COUP-TF2 as a human “pro-ovary” and “anti-testis” sex-determining factor in female gonads. Furthermore, the data presented here provide additional evidence of the emerging importance of nuclear receptors in establishing human ovarian identity and indicate that nuclear receptors may have divergent functions in mouse and human biology.

Monogenic Hypertension in Children: A Review With Emphasis on Genetics

Hypertension (HT) is a public health problem in children particularly related to the epidemic of overweight and obesity. Monogenic forms of HT are important in the differential diagnosis in children presenting with severe or refractory HT, who have a family history of early-onset HT, unusual physical examination findings, and/or characteristic hormonal and biochemical abnormalities. Most genetic defects in these disorders ultimately result in increased sodium transport in the distal nephron resulting in volume expansion and HT. Genetic testing, which is increasingly available, has diagnostic, therapeutic, and predictive implications for families affected by these rare conditions.

YY1 Haploinsufficiency Causes an Intellectual Disability Syndrome Featuring Transcriptional and Chromatin Dysfunction

Yin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and as an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features that define a syndrome of cognitive impairment, behavioral alterations, intrauterine growth restriction, feeding problems, and various congenital malformations. Our combined clinical and molecular data define "YY1 syndrome" as a haploinsufficiency syndrome. Through immunoprecipitation of YY1-bound chromatin from affected individuals' cells with antibodies recognizing both ends of the protein, we show that YY1 deletions and missense mutations lead to a global loss of YY1 binding with a preferential retention at high-occupancy sites. Finally, we uncover a widespread loss of H3K27 acetylation in particular on the YY1-bound enhancers, underscoring a crucial role for YY1 in enhancer regulation. Collectively, these results define a clinical syndrome caused by haploinsufficiency of YY1 through dysregulation of key transcriptional regulators.

Novel homozygous likely-pathogenic intronic variant in INS causing permanent neonatal diabetes in siblings

Permanent neonatal diabetes (PNDM) is a rare genetic condition characterized by hyperglycemia, insulinopenia, and failure to thrive beginning in the first 6 months of life. Recessive mutations in INS lead to decreased production of insulin via a variety of mechanisms. We present a case of two brothers, born to consanguineous parents, with a novel homozygous intronic variant in the INS gene. Each patient presented with intrauterine growth restriction (IUGR) and significant hyperglycemia within the first 24 h of life. All the grandparents have a diagnosis of diabetes, one of them requiring insulin treatment and the parents currently deny personal histories of diabetes. Although this mutation has not previously been described, given the segregation of the mutation, absence of heterozygosity (AOH) in the genomic region encompassing the INS locus, documented insulinopenia, and high neonatal insulin requirements, we suspect that this variant is pathogenic. Possible implications for personalized treatment of the underlying molecular etiology for an individual's diabetes are discussed.