Maternal and prenatal factors and age at thelarche in the LEGACY Girls Study cohort: implications for breast cancer risk.

2023

272-283

02/2023

1464-3685

BACKGROUND: Earlier onset of breast development (thelarche) is associated with increased breast cancer risk. Identifying modifiable factors associated with earlier thelarche may provide an opportunity for breast cancer risk reduction starting early in life, which could especially benefit girls with a greater absolute risk of breast cancer due to family history.

METHODS: We assessed associations of maternal pre-pregnancy body mass index (BMI), physical activity during pregnancy, gestational weight gain and daughters' weight and length at birth with age at thelarche using longitudinal Weibull models in 1031 girls in the Lessons in Epidemiology and Genetics of Adult Cancer from Youth (LEGACY) Girls Study-a prospective cohort of girls, half of whom have a breast cancer family history (BCFH).

RESULTS: Girls whose mothers had a pre-pregnancy BMI of ≥25 and gained ≥30 lbs were 57% more likely to experience earlier thelarche than girls whose mothers had a pre-pregnancy BMI of <25 and gained <30 lbs [hazard ratio (HR) = 1.57, 95% CI: 1.16, 2.12]. This association was not mediated by childhood BMI and was similar in girls with and without a BCFH (BCFH: HR = 1.41, 95% CI: 0.87, 2.27; No BCFH: HR = 1.62, 95% CI: 1.10, 2.40). Daughters of women who reported no recreational physical activity during pregnancy were more likely to experience earlier thelarche compared with daughters of physically active women. Birthweight and birth length were not associated with thelarche.

CONCLUSION: Earlier thelarche, a breast cancer risk factor, was associated with three potentially modifiable maternal risk factors-pre-pregnancy BMI, gestational weight gain and physical inactivity-in a cohort of girls enriched for BCFH.

10.1093/ije/dyac108

Int J Epidemiol

35613015

Body mass index rebound and pubertal timing in girls with and without a family history of breast cancer: the LEGACY girls study.

2022

1546-1555

12/2022

1464-3685

BACKGROUND: Heavier body mass index (BMI) is the most established predictor of earlier age at puberty. However, it is unknown whether the timing of the childhood switch to heavier BMI (age at BMI rebound) also matters for puberty.

METHODS: In the LEGACY Girls Study (n = 1040), a longitudinal cohort enriched with girls with a family history of breast cancer, we collected paediatric growth chart data from 852 girls and assessed pubertal development every 6 months. Using constrained splines, we interpolated individual growth curves and then predicted BMI at ages 2, 4, 6, 8 and 9 years for 591 girls. We defined age at BMI rebound as the age at the lowest BMI between ages 2 and 8 years and assessed its association with onset of thelarche, pubarche and menarche using Weibull survival models.

RESULTS: The median age at BMI rebound was 5.3 years (interquartile range: 3.6-6.7 years). A 1-year increase in age at BMI rebound was associated with delayed thelarche (HR = 0.90; 95% CI = 0.83-0.97) and menarche (HR = 0.86; 95% CI = 0.79-0.94). The magnitude of these associations remained after adjusting for weight between birth and 2 years, was stronger after adjusting for BMI at age 9, and was stronger in a subset of girls with clinically assessed breast development.

CONCLUSIONS: Earlier BMI rebound is associated with earlier pubertal timing. Our observation that BMI rebound may be a driver of pubertal timing in girls with and without a family history of breast cancer provides insight into how growth and pubertal timing are associated with breast cancer risk.

10.1093/ije/dyac021

Int J Epidemiol

35157067

Maternal and prenatal factors and age at thelarche in the LEGACY Girls Study cohort: implications for breast cancer risk.

2022

05/2022

1464-3685

BACKGROUND: Earlier onset of breast development (thelarche) is associated with increased breast cancer risk. Identifying modifiable factors associated with earlier thelarche may provide an opportunity for breast cancer risk reduction starting early in life, which could especially benefit girls with a greater absolute risk of breast cancer due to family history.

METHODS: We assessed associations of maternal pre-pregnancy body mass index (BMI), physical activity during pregnancy, gestational weight gain and daughters' weight and length at birth with age at thelarche using longitudinal Weibull models in 1031 girls in the Lessons in Epidemiology and Genetics of Adult Cancer from Youth (LEGACY) Girls Study-a prospective cohort of girls, half of whom have a breast cancer family history (BCFH).

RESULTS: Girls whose mothers had a pre-pregnancy BMI of ≥25 and gained ≥30 lbs were 57% more likely to experience earlier thelarche than girls whose mothers had a pre-pregnancy BMI of <25 and gained <30 lbs [hazard ratio (HR) = 1.57, 95% CI: 1.16, 2.12]. This association was not mediated by childhood BMI and was similar in girls with and without a BCFH (BCFH: HR = 1.41, 95% CI: 0.87, 2.27; No BCFH: HR = 1.62, 95% CI: 1.10, 2.40). Daughters of women who reported no recreational physical activity during pregnancy were more likely to experience earlier thelarche compared with daughters of physically active women. Birthweight and birth length were not associated with thelarche.

CONCLUSION: Earlier thelarche, a breast cancer risk factor, was associated with three potentially modifiable maternal risk factors-pre-pregnancy BMI, gestational weight gain and physical inactivity-in a cohort of girls enriched for BCFH.

10.1093/ije/dyac108

Int J Epidemiol

35613015

Mother and daughter perspectives on genetic counseling and testing of adolescents for hereditary breast cancer risk.

2022

06/2022

1097-6833

OBJECTIVE: To evaluate the risks, benefits, and utility of testing for adult-onset hereditary breast and ovarian cancer (HBOC) in adolescents and young adults.

STUDY DESIGN: We evaluated interest in genetic testing of adolescents for adult-onset HBOC genes through semistructured interviews with mothers and adolescents who had previously participated in breast cancer research or had pursued (mothers) clinical testing for HBOC.

RESULTS: The majority of mothers (73%) and daughters (75%) were interested in the daughter having genetic testing and were motivated by the future medical utility and current social utility of relieving anxiety and allowing them to prepare. Mothers and daughters both reported that approximately 3 years in the future was the best time to test the daughter regardless of the current age of the daughter. Overall, both mothers and daughters expressed the importance of the involvement of the mother to provide educational and emotional support but ultimately it was the daughter's decision to test. Balancing the independence and maturity of the daughter while reinforcing communication and support within the dyad was a prominent theme throughout the interviews.

CONCLUSIONS: There is interest among some high-risk adolescents and young adults to engage in genetic counseling and undergo testing. Providing pretest and posttest genetic counseling, assessing preferences for parent involvement, and offering psychosocial support may be important if genetic testing for HBOC is offered to adolescents and young adults before age 25 years.

10.1016/j.jpeds.2022.06.027

J Pediatr

35777474

Body mass index rebound and pubertal timing in girls with and without a family history of breast cancer: the LEGACY girls study.

2022

2022 Feb 14

1464-3685

<p><strong>BACKGROUND: </strong>Heavier body mass index (BMI) is the most established predictor of earlier age at puberty. However, it is unknown whether the timing of the childhood switch to heavier BMI (age at BMI rebound) also matters for puberty.</p>

<p><strong>METHODS: </strong>In the LEGACY Girls Study (n = 1040), a longitudinal cohort enriched with girls with a family history of breast cancer, we collected paediatric growth chart data from 852 girls and assessed pubertal development every 6 months. Using constrained splines, we interpolated individual growth curves and then predicted BMI at ages 2, 4, 6, 8 and 9 years for 591 girls. We defined age at BMI rebound as the age at the lowest BMI between ages 2 and 8 years and assessed its association with onset of thelarche, pubarche and menarche using Weibull survival models.</p>

<p><strong>RESULTS: </strong>The median age at BMI rebound was 5.3 years (interquartile range: 3.6-6.7 years). A 1-year increase in age at BMI rebound was associated with delayed thelarche (HR = 0.90; 95% CI = 0.83-0.97) and menarche (HR = 0.86; 95% CI = 0.79-0.94). The magnitude of these associations remained after adjusting for weight between birth and 2 years, was stronger after adjusting for BMI at age 9, and was stronger in a subset of girls with clinically assessed breast development.</p>

<p><strong>CONCLUSIONS: </strong>Earlier BMI rebound is associated with earlier pubertal timing. Our observation that BMI rebound may be a driver of pubertal timing in girls with and without a family history of breast cancer provides insight into how growth and pubertal timing are associated with breast cancer risk.</p>

10.1093/ije/dyac021

Int J Epidemiol

35157067

The genetic architecture of pediatric cardiomyopathy.

2022

2022 Jan 10

1537-6605

<p>To understand the genetic contribution to primary pediatric cardiomyopathy, we performed exome sequencing in a large cohort of 528 children with cardiomyopathy. Using clinical interpretation guidelines and targeting genes implicated in cardiomyopathy, we identified a genetic cause in 32% of affected individuals. Cardiomyopathy sub-phenotypes differed by ancestry, age at diagnosis, and family history. Infants &lt; 1 year were less likely to have a molecular diagnosis (p &lt; 0.001). Using a discovery set of 1,703 candidate genes and informatic tools, we identified rare and damaging variants in 56% of affected individuals. We see an excess burden of damaging variants in affected individuals as compared to two independent control sets, 1000 Genomes Project (p &lt; 0.001) and SPARK parental controls (p &lt; 1&nbsp;× 10). Cardiomyopathy variant burden remained enriched when stratified by ancestry, variant type, and sub-phenotype, emphasizing the importance of understanding the contribution of these factors to genetic architecture. Enrichment in this discovery candidate gene set suggests multigenic mechanisms underlie sub-phenotype-specific causes and presentations of cardiomyopathy. These results identify important information about the genetic architecture of pediatric cardiomyopathy and support recommendations for clinical genetic testing in children while illustrating differences in genetic architecture by age, ancestry, and sub-phenotype and providing rationale for larger studies to investigate multigenic contributions.</p>

10.1016/j.ajhg.2021.12.006

Am J Hum Genet

35026164

Impact of Genetic Testing for Cardiomyopathy on Emotional Well-Being and Family Dynamics: A Study of Parents and Adolescents.

2021

CIRCGEN120003189

2021 Jul 13

2574-8300

<p><strong>BACKGROUND: </strong>Genetic testing is indicated for children with a personal or family history of hereditary cardiomyopathy to determine appropriate management and inform risk stratification for family members. The implications of a positive genetic result for children can potentially impact emotional well-being. Given the nuances of cardiomyopathy genetic testing for minors, this study aimed to understand how parents involve their children in the testing process and investigate the impact of genetic results on family dynamics.</p>

<p><strong>METHODS: </strong>A survey was distributed to participants recruited from the Children's Cardiomyopathy Foundation and 7 North American sites in the Pediatric Cardiomyopathy Registry. The survey explored adolescent and parent participants' emotions upon receiving their/their child's genetic results, parent-child result communication and its impact on family functionality, using the McMaster Family Assessment Device.</p>

<p><strong>RESULTS: </strong>One hundred sixty-two parents of minors and 48 adolescents who were offered genetic testing for a personal or family history of cardiomyopathy completed the survey. Parents whose child had cardiomyopathy were more likely to disclose positive diagnostic genetic results to their child (=0.014). Parents with unaffected children and positive predictive testing results were more likely to experience negative emotions about the result (≤0.001) but also had better family functioning scores than those with negative predictive results (=0.019). Most adolescents preferred results communicated directly to the child, but parents were divided about whether their child's result should first be released to them or their child.</p>

<p><strong>CONCLUSIONS: </strong>These findings have important considerations for how providers structure genetic services for adolescents and facilitate discussion between parents and their children about results.</p>

10.1161/CIRCGEN.120.003189

Circ Genom Precis Med

34255550

Genetic Causes of Cardiomyopathy in Children: First Results From the Pediatric Cardiomyopathy Genes Study.

2021

e017731

2021 Apr 28

2047-9980

<p>Background Pediatric cardiomyopathy is a genetically heterogeneous disease with substantial morbidity and mortality. Current guidelines recommend genetic testing in children with hypertrophic, dilated, or restrictive cardiomyopathy, but practice variations exist. Robust data on clinical testing practices and diagnostic yield in children are lacking. This study aimed to identify the genetic causes of cardiomyopathy in children and to investigate clinical genetic testing practices. Methods and Results Children with familial or idiopathic cardiomyopathy were enrolled from 14 institutions in North America. Probands underwent exome sequencing. Rare sequence variants in 37 known cardiomyopathy genes were assessed for pathogenicity using consensus clinical interpretation guidelines. Of the 152 enrolled probands, 41% had a family history of cardiomyopathy. Of 81 (53%) who had undergone clinical genetic testing for cardiomyopathy before enrollment, 39 (48%) had a positive result. Genetic testing rates varied from 0% to 97% between sites. A positive family history and hypertrophic cardiomyopathy subtype were associated with increased likelihood of genetic testing (=0.005 and =0.03, respectively). A molecular cause was identified in an additional 21% of the 63 children who did not undergo clinical testing, with positive results identified in both familial and idiopathic cases and across all phenotypic subtypes. Conclusions A definitive molecular genetic diagnosis can be made in a substantial proportion of children for whom the cause and heritable nature of their cardiomyopathy was previously unknown. Practice variations in genetic testing are great and should be reduced. Improvements can be made in comprehensive cardiac screening and predictive genetic testing in first-degree relatives. Overall, our results support use of routine genetic testing in cases of both familial and idiopathic cardiomyopathy. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01873963.</p>

10.1161/JAHA.120.017731

J Am Heart Assoc

33906374

Common Childhood Viruses and Pubertal Timing: The LEGACY Girls Study.

2020

2020 Oct 31

1476-6256

<p>Earlier pubertal development is only partially explained by childhood body mass index (BMI); the role of other factors like childhood infections is less understood. Using data from the LEGACY Girls Study (2011 - 2016), we prospectively examined the associations between childhood viral infections (Cytomegalovirus (CMV), Epstein Barr Virus (EBV), Herpes Simplex Virus 1 (HSV1), HSV2 and pubertal timing. We measured exposures based on seropositivity in pre-menarcheal girls (n=490). Breast and pubic hair development were classified based on mother-reported Tanner Stage (TS: TS2+ compared with TS1), adjusting for age, BMI, and sociodemographic factors. The average age at first blood draw was 9.8 years (Stdev=1.9 years). The prevalences were 31% CMV+, 37% EBV+, 14% HSV1+, 0.4% HSV2+, and 16% for both CMV+/EBV+. CMV+ infection without co-infection was associated with developing breasts an average of 7 months earlier (Hazard Ratio (HR)=2.12, 95% CI 1.32, 3.40). CMV+ infection without co-infection and HSV1+ and/or HSV2+ infection were associated with developing pubic hair 9 months later (HR 0.41, 95% CI 0.24, 0.71, HR 0.42, 95% CI 0.22, 0.81, respectively). Infection was not associated with menarche. If replicated in larger cohorts with blood collection prior to any breast development, this study supports that childhood infections may play a role in altering pubertal timing.</p>

10.1093/aje/kwaa240

Am J Epidemiol

33128063

Pediatric Cardiomyopathies.

2017

855-873

2017 Sep 15

1524-4571

<p>Pediatric cardiomyopathies are rare diseases with an annual incidence of 1.1 to 1.5 per 100 000. Dilated and hypertrophic cardiomyopathies are the most common; restrictive, noncompaction, and mixed cardiomyopathies occur infrequently; and arrhythmogenic right ventricular cardiomyopathy is rare. Pediatric cardiomyopathies can result from coronary artery abnormalities, tachyarrhythmias, exposure to infection or toxins, or secondary to other underlying disorders. Increasingly, the importance of genetic mutations in the pathogenesis of isolated or syndromic pediatric cardiomyopathies is becoming apparent. Pediatric cardiomyopathies often occur in the absence of comorbidities, such as atherosclerosis, hypertension, renal dysfunction, and diabetes mellitus; as a result, they offer insights into the primary pathogenesis of myocardial dysfunction. Large international registries have characterized the epidemiology, cause, and outcomes of pediatric cardiomyopathies. Although adult and pediatric cardiomyopathies have similar morphological and clinical manifestations, their outcomes differ significantly. Within 2 years of presentation, normalization of function occurs in 20% of children with dilated cardiomyopathy, and 40% die or undergo transplantation. Infants with hypertrophic cardiomyopathy have a 2-year mortality of 30%, whereas death is rare in older children. Sudden death is rare. Molecular evidence indicates that gene expression differs between adult and pediatric cardiomyopathies, suggesting that treatment response may differ as well. Clinical trials to support evidence-based treatments and the development of disease-specific therapies for pediatric cardiomyopathies are in their infancy. This compendium summarizes current knowledge of the genetic and molecular origins, clinical course, and outcomes of the most common phenotypic presentations of pediatric cardiomyopathies and highlights key areas where additional research is required.</p>

<p><strong>CLINICAL TRIAL REGISTRATION: </strong>URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02549664 and NCT01912534.</p>

10.1161/CIRCRESAHA.116.309386

Circ. Res.

28912187