Clinical presentation and genetics of tricho-rhino-phalangeal syndrome (TRPS) type 1: A single-center case series of 15 patients and seven novel TRPS1 variants

Tricho-rhino-phalangeal syndrome (TRPS) is a rare malformation syndrome characterized by distinctive facial, ectodermal, and skeletal features. TRPS is divided into TRPS type I/III caused by pathogenic variants in TRPS1 and TRPS type II caused by contiguous gene deletions also spanning EXT1 and RAD21. Due to its rarity, knowledge of the clinical course of TRPS remains limited. Therefore, we collected and characterized a case series of 15 TRPS type I patients (median age at diagnosis 15 [interquartile range: 10-18] years, 11 females [73%]) seen at Aarhus University Hospital, Denmark, with a median follow-up period of 10 years. We estimated a minimum point prevalence of 0.5 in 100,000 (95% CI: 0.3-0.8 per 100,000) persons. Common craniofacial features included fine and sparse hair with a high anterior hairline, eyebrows with lateral thinning and a thicker medial part, prominent ears, a bulbous nose tip with small nasal alae, a low-hanging, and often wide columella, and a long philtrum with a thin upper vermillion. Specific skeletal features included short stature and deviating and short fingers with cone-shaped epiphyses and shortened metacarpals on radiographs. The most significant morbidity of the cohort was joint complaints, which were reported by all patients, often already before the TRPS diagnosis was established. We identified ten different TRPS1 variants including both frameshift/nonsense, missense, and splice-site variants, including seven variants not previously reported in the literature. In accordance with previous literature, no genotype-phenotype correlation was identified. The clinical trajectories were heterogeneous involving pediatrics, dermatology, orthopedic surgery, clinical genetics, and/or odontology, emphasizing that close multidisciplinary collaboration is essential for early diagnosis of TRPS and to ensure proper and timely patient care and counseling.

Prevalence and Patient Characteristics of Ectodermal Dysplasias in Denmark

Importance

Ectodermal dysplasias constitute a group of rare genetic disorders of the skin and skin appendages with hypodontia, hypotrichosis, and hypohidrosis as cardinal features. There is a lack of population-based research into the epidemiology of ectodermal dysplasias.

Objective

To establish a validated population-based cohort of patients with ectodermal dysplasia in Denmark and to assess the disease prevalence and patient characteristics.

Design, Setting, and Participants

This nationwide cohort study used individual-level registry data recorded across the Danish universal health care system to identify patients with ectodermal dysplasias from January 1, 1995, to August 25, 2021. A 3-level search of the Danish National Patient Registry and the Danish National Child Odontology Registry was conducted to identify patients with diagnosis codes indicative of ectodermal dysplasias; patients registered in the Danish RAREDIS Database, the Danish Database of Genodermatoses, and local databases were also added. The search results underwent diagnosis validation and review of clinical data using medical records. Of 844 patient records suggestive of ectodermal dysplasias, 791 patients (93.7%) had medical records available for review. Positive predictive values of the diagnosis coding were computed, birth prevalence was estimated, and patient characteristics were identified. Data analysis was performed from May 4 to December 22, 2023.

Results

The identified and validated study cohort included 396 patients (median [IQR] age at diagnosis, 13 [4-30] years, 246 females [62.1%]), of whom 319 had confirmed ectodermal dysplasias and 77 were likely cases. The combined positive predictive value (PPV) for ectodermal dysplasia-specific diagnosis codes was 67.0% (95% CI, 62.7%-71.0%). From 1995 to 2011, the estimated minimum birth prevalence per 100 000 live births was 14.5 (95% CI, 12.2-16.7) for all ectodermal dysplasias and 2.8 (95% CI, 1.8-3.8) for X-linked hypohidrotic ectodermal dysplasias. A molecular genetic diagnosis was available for 241 patients (61%), including EDA (n = 100), IKBKG (n = 55), WNT10A (n = 21), TRPS1 (n = 18), EDAR (n = 10), P63 (n = 9), GJB6 (n = 9), PORCN (n = 7), and other rare genetic variants.

Conclusions and Relevance

The findings of this nationwide cohort study indicate that the prevalence of ectodermal dysplasias was lower than previously reported. Furthermore, PPVs of the search algorithms emphasized the importance of diagnosis validation. The establishment of a large nationwide cohort of patients with ectodermal dysplasias, including detailed clinical and molecular data, is a unique resource for future research in ectodermal dysplasias.

Identifying primary and secondary MLH1 epimutation carriers displaying low-level constitutional MLH1 methylation using droplet digital PCR and genome-wide DNA methylation profiling of colorectal cancers

BACKGROUND

MLH1 epimutation is characterised by constitutional monoallelic MLH1 promoter hypermethylation, which can cause colorectal cancer (CRC). Tumour molecular profiles of MLH1 epimutation CRCs were used to classify germline MLH1 promoter variants of uncertain significance and MLH1 methylated early-onset CRCs (EOCRCs). Genome-wide DNA methylation and somatic mutational profiles of tumours from two germline MLH1: c.-11C > T and one MLH1: c.-[28A > G; 7C > T] carriers and three MLH1 methylated EOCRCs (< 45 years) were compared with 38 reference CRCs. Methylation-sensitive droplet digital PCR (ddPCR) was used to detect mosaic MLH1 methylation in blood, normal mucosa and buccal DNA.

RESULTS

Genome-wide methylation-based Consensus Clustering identified four clusters where the tumour methylation profiles of germline MLH1: c.-11C > T carriers and MLH1 methylated EOCRCs clustered with the constitutional MLH1 epimutation CRCs but not with the sporadic MLH1 methylated CRCs. Furthermore, monoallelic MLH1 methylation and APC promoter hypermethylation in tumour were observed in both MLH1 epimutation and germline MLH1: c.-11C > T carriers and MLH1 methylated EOCRCs. Mosaic constitutional MLH1 methylation in MLH1: c.-11C > T carriers and 1 of 3 MLH1 methylated EOCRCs was identified by methylation-sensitive ddPCR.

CONCLUSIONS

Mosaic MLH1 epimutation underlies the CRC aetiology in MLH1: c.-11C > T germline carriers and a subset of MLH1 methylated EOCRCs. Tumour profiling and ultra-sensitive ddPCR methylation testing can be used to identify mosaic MLH1 epimutation carriers.

[Aquagenic wrinkling of the palms is a rare dermatological disease associated with cystic fibrosis]

Aquagenic wrinkling of the palms was first described in 1974. This review summarises the present knowledge. Aquagenic wrinkling of the palms is most often associated with cystic fibrosis, but several other associated conditions are described. Patients report of pruritus, pain and discomfort in the palms after contact with water, and excessive wrinkling is visible. The prognosis is good, and symptoms often decrease in adulthood. A positive water exposure test will support the diagnosis, and the patient should be referred for dermatological investigation and genetic test for cystic fibrosis should be offered.

Novel TRPV4 variant causes a severe form of metatropic dysplasia

We present a girl born with a frontal bossing, short neck, bell-shaped thorax, short limbs with prominent joints, and a tail-like coccygeal appendage. Genetic screening of TRPV4 identified a novel de novo heterozygous missense variant. We believe the variant causes the severe form of metatropic dysplasia in this patient.

Body mass index trajectories from 2 to 18 years - exploring differences between European cohorts

BACKGROUND

In recent decades, there has been an increase in the prevalence of childhood overweight in most high-income countries. Within northern Europe, prevalence tends to be higher in the UK compared with the Scandinavian countries. We aimed to study differences in body mass index (BMI) trajectories between large cohorts of children from UK and Scandinavian populations.

METHODS

We compared BMI trajectories in participants from the English Avon Longitudinal Study of Parents and Children born in 1991-1993 (ALSPAC) (N = 6517), the Northern Finland Birth Cohorts born in 1966 (NFBC1966) (N = 3321) and 1986 (NFBC1986) (N = 4764), and the Danish Aarhus Birth Cohort born in 1990-1992 (ABC) (N = 1920). We used multilevel models to estimate BMI trajectories from 2 to 18 years. We explored whether cohort differences were explained by maternal BMI, height, education or smoking during pregnancy and whether differences were attributable to changes in the degree of skew in the BMI distribution.

RESULTS

Differences in mean BMI between the cohorts were small but emerged early and persisted in most cases across childhood. Girls in ALSPAC had a higher BMI than all other cohorts throughout childhood, e.g. compared with the NFBC1986 BMI was 2.2-3.5% higher. For boys, the difference emerging over time (comparing the two NFBC's) exceeded the differences across populations (comparing NFBC1986, ABC and ALSPAC). BMI distribution demonstrated increasing right skew with age.

CONCLUSION

Population-level differences between cohorts were small, tended to emerge very early, persisted across childhood, and demonstrated an increase in the right-hand tail of the BMI distribution.

Prediction of adolescent and adult adiposity outcomes from early life anthropometrics

OBJECTIVES

Maternal body mass index (BMI), birth weight, and preschool BMI may help identify children at high risk of overweight as they are (1) similarly linked to adolescent overweight at different stages of the obesity epidemic, (2) linked to adult obesity and metabolic alterations, and (3) easily obtainable in health examinations in young children. The aim was to develop early childhood prediction models of adolescent overweight, adult overweight, and adult obesity.

METHODS

Prediction models at various ages in the Northern Finland Birth Cohort born in 1966 (NFBC1966) were developed. Internal validation was tested using a bootstrap design, and external validation was tested for the model predicting adolescent overweight using the Northern Finland Birth Cohort born in 1986 (NFBC1986).

RESULTS

A prediction model developed in the NFBC1966 to predict adolescent overweight, applied to the NFBC1986, and aimed at labelling 10% as "at risk" on the basis of anthropometric information collected until 5 years of age showed that half of those at risk in fact did become overweight. This group constituted one-third of all who became overweight.

CONCLUSIONS

Our prediction model identified a subgroup of children at very high risk of becoming overweight, which may be valuable in public health settings dealing with obesity prevention.

Stability of the associations between early life risk indicators and adolescent overweight over the evolving obesity epidemic

Background

Pre- and perinatal factors and preschool body size may help identify children developing overweight, but these factors might have changed during the development of the obesity epidemic.

Objective

We aimed to assess the associations between early life risk indicators and overweight at the age of 9 and 15 years at different stages of the obesity epidemic.

Methods

We used two population-based Northern Finland Birth Cohorts including 4111 children born in 1966 (NFBC1966) and 5414 children born in 1985–1986 (NFBC1986). In both cohorts, we used the same a priori defined prenatal factors, maternal body mass index (BMI), birth weight, infant weight (age 5 months and 1 year), and preschool BMI (age 2–5 years). We used internal references in early childhood to define percentiles of body size (<50, 50–75, 75–90 and >90) and generalized linear models to study the association with overweight, according to the International Obesity Taskforce (IOTF) definitions, at the ages of 9 and 15 years.

Results

The prevalence of overweight at the age of 15 was 9% for children born in 1966 and 16% for children born in 1986. However, medians of infant weight and preschool BMI changed little between the cohorts, and we found similar associations between maternal BMI, infant weight, preschool BMI, and later overweight in the two cohorts. At 5 years, children above the 90^th percentile had approximately a 12 times higher risk of being overweight at the age of 15 years compared to children below the 50^th percentile in both cohorts.

Conclusions

The associations between early body size and adolescent overweight showed remarkable stability, despite the increase in prevalence of overweight over the 20 years between the cohorts. Using consequently defined internal percentiles may be a valuable tool in clinical practice.

Preschool weight and body mass index in relation to central obesity and metabolic syndrome in adulthood

BACKGROUND

If preschool measures of body size routinely collected at preventive health examinations are associated with adult central obesity and metabolic syndrome, a focused use of these data for the identification of high risk children is possible. The aim of this study was to test the associations between preschool weight and body mass index (BMI) and adult BMI, central obesity and metabolic alterations.

METHODS

The Northern Finland Birth Cohort 1966 (NFBC1966) (N = 4111) is a population-based cohort. Preschool weight (age 5 months and 1 year) and BMI (age 2-5 years) were studied in relation to metabolic syndrome as well as BMI, waist circumference, lipoproteins, blood pressure, and fasting glucose at the age of 31 years. Linear regression models and generalized linear regression models with log link were used.

RESULTS

Throughout preschool ages, weight and BMI were significantly linearly associated with adult BMI and waist circumference. Preschool BMI was inversely associated with high-density lipoprotein levels from the age of 3 years. Compared with children in the lower half of the BMI range, the group of children with the 5% highest BMI at the age of 5 years had a relative risk of adult obesity of 6.2(95% CI:4.2-9.3), of adult central obesity of 2.4(95% CI:2.0-2.9), and of early onset adult metabolic syndrome of 2.5(95% CI:1.7-3.8).

CONCLUSIONS

High preschool BMI is consistently associated with adult obesity, central obesity and early onset metabolic syndrome. Routinely collected measures of body size in preschool ages can help to identify children in need of focused prevention due to their increased risk of adverse metabolic alterations in adulthood.

Lipid-lowering drugs as primary prevention in general practice: do patients reach guideline goals and continue treatment? ADDITION Denmark

OBJECTIVE

To describe lipid-lowering treatment in a primary care setting and how well target levels are reached. Furthermore, the aim is to describe long-term adherence to treatment.

DESIGN

Population-based cross-sectional study with follow-up.

SETTING

A total of 139 general practices from three of five Danish regions, taking part in the ADDITION study from 2001 to 2006.

SUBJECTS

The study population comprises 1468 patients who started lipid-lowering drugs and were followed for a minimum of one year after starting treatment. Median time of follow-up after starting drug therapy was 936 days (range: 366-2068).

RESULTS

Of 1468 patients starting treatment, a total of 781 (53%) reached the treatment goal of total cholesterol <5.0 and low-density lipoprotein <3 mmol/l within one year after drug therapy start. The percentage increased throughout the study period from 27% of patients initiating treatment in 2001 to 66% of patients initiating treatment in 2005. Age over 50, repeated cholesterol measurements within three months after treatment start, larger initial dose, and calendar year of treatment start were associated with reaching the goal within the first year, and most recent total cholesterol measurement before start of treatment >7 mmol/L was associated with not reaching the goal in the first year. Among patients followed for a minimum of three years after drug therapy started (n = 536), adherence was 77%, 72%, 75% in the first, second, and third year respectively.

CONCLUSION

Initial doses and the percentage reaching their goal increased substantially throughout the study period. Adherence to lipid-lowering treatment is relatively high in a primary care setting. However, current practice shows room for improvement if treatment recommendations are to be met.

General practitioners' adherence to guidelines on management of dyslipidaemia: ADDITION-Denmark

OBJECTIVE

To describe the management of dyslipidaemia in patients with high risk of cardiovascular disease (CVD) and patients with a history of CVD identified by screening for diabetes in general practice in Denmark, concentrating on prescription of lipid-lowering drugs. Moreover, to analyse predicting factors for starting lipid-lowering drugs related to patient and general practice characteristics.

DESIGN

Population-based cross-sectional study with follow-up.

SETTING

A total of 139 general practices from three of five Danish regions, totalling 216 GPs.

SUBJECTS

The study population comprised 4986 patients with a high risk of CVD and dyslipidaemia and 764 patients with a history of CVD and dyslipidaemia out of a population of 16 572 patients who completed screening for diabetes but were cleared for diabetes in the ADDITION study.

RESULTS

Of patients with a high risk of CVD and dyslipidaemia not receiving lipid-lowering drugs at the time of screening (n = 4823), 20% started lipid-lowering therapy within the follow-up period (median 2.1 years). This percentage was 45% (n = 536) for patients with CVD and dyslipidaemia (median follow-up period 1.6 years). Age over 50, high cholesterol, impaired fasting glucose and/or impaired glucose tolerance, minor polypharmacy, use of heart/circulation drugs, and cholesterol measurements after screening predicted the prescription of lipid-lowering drugs for patients at high risk of CVD. For patients with CVD, male gender, high cholesterol and use of heart/circulation drugs predicted the prescription of lipid-lowering drugs. No general practice characteristics were associated with different prescription habits.

CONCLUSION

There is a gap between the recommended lipid-lowering drug therapy and current practice, with a substantial under-treatment and a considerable delay in the first prescription of lipid-lowering drugs.

The role of DNA polymerase beta in determining sensitivity to ionizing radiation in human tumor cells

Lethal lesions after ionizing radiation are thought to be mainly unrepaired or misrepaired DNA double-strand breaks, ultimately leading to lethal chromosome aberrations. However, studies with radioprotectors and repair inhibitors indicate that single-strand breaks, damaged nucleotides or abasic sites can also influence cell survival. This paper reports on studies to further define the role of base damage and base excision repair on the radiosensitivity of human cells. We retrovirally transduced human tumor cells with a dominant negative form of DNA polymerase beta, comprising the 14 kDa DNA-binding domain of DNA polymerase beta but lacking polymerase function. Radiosensitization of two human carcinoma cell lines, A549 and SQD9, was observed, achieving dose enhancement factors of 1.5-1.7. Sensitization was dependent on expression level of the dominant negative and was seen in both single cell clones and in unselected virally transduced populations. Sensitization was not due to changes in cell cycle distribution. Little or no sensitization was seen in G(1)-enriched populations, indicating cell cycle specificity for the observed sensitization. These results contrast with the lack of effect seen in DNA polymerase beta knockout cells, suggesting that polDN also inhibits the long patch, DNA polymerase beta-independent repair pathway. These data demonstrate an important role for BER in determining sensitivity to ionizing radiation and might help identify targets for radiosensitizing tumor cells.

[Changes of knowledge of HIV-positivity before development of AIDS among Danish patients with AIDS 1988-1997]

We describe the changes in the period of knowledge of HIV positivity before AIDS in the light of the new anti-retroviral treatment regime among all notified Danish AIDS patients 1988-1997. Overall, 29% of the patients were diagnosed with AIDS less than four months after the first positive HIV test, a proportion that decreased through 1988-1995, but then increased. However, the proportion with over five years between positive HIV test and AIDS diagnosis increased from 9% in 1988-1990 to 48% in 1994-1995. A similar trend was seen among men, who have sex with men (MSM). Relatively more heterosexually infected than MSM had less than four months between first positive HIV test and AIDS (44% vs. 25%, p < 0.00001). Among persons known as HIV infected less than four months before AIDS, 51% were notified with Pneumocystis carinii pneumonia, a proportion that was 25% (p < 0.00001) among those known over five years before AIDS. We conclude, that the proportion of Danish AIDS patients known as HIV-infected for less than four months before AIDS recently has increased after several years of decrease, probably due to anti-retroviral treatment.