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Objective: This study aims to evaluate the neonatal screening for congenital hypothyroidism (CH) and the diagnosis CH in the national health registers and to study the effects of lowering screening thyroid-stimulating hormone (TSH) threshold on the incidence of CH and birth characteristics of screening positive and negative CH children. Design: This is a nationwide register-study of all children (n = 3 427 240) in the Swedish Medical Birth Register (MBR) and national cohort for screening positive infants (n = 1577) in 1980-2013. Methods: The study population was further linked to several other Swedish health registers. Evaluation of the CH screening and CH diagnosis was performed with levothyroxine use in the first year of life as reference. The incidence of CH was estimated by the Clopper-Pearson method. Regression models were used to study associations between CH and birth characteristics. Results: The neonatal CH screening had high efficacy, but 50% of all children with a CH diagnosis were screening negative. The incidence of screening positive CH increased (1/3375 to 1/2222), and the incidence of screening negative CH decreased (1/2563 to 1/7841) after lowering the TSH screening threshold in 2009. Screening negative CH was associated with female sex, twinning, prematurity, low birth weight, birth defects, and need of neonatal intensive care, and 42% had transient disease. Conclusions: Despite high efficacy of the CH screening, 50% of children diagnosed as CH was screening negative. Although other factors influencing the incidence of the CH diagnosis cannot be ruled out, the incidence of screening negative CH decreased with lowering of the TSH threshold. Birth characteristics differed between screening positive and negative CH. [ABSTRACT FROM AUTHOR]

Conclusion: The most common mutation in the Swedish population was Connexin 26 (C×26) 35delG, which indicates that the percentage of Swedish persons with C×26 mutations and polymorphisms in the GJB2 gene among non-syndromic hearing-impaired (HI) persons is comparable to the rest of Europe. The results strongly support a Swedish policy to offer all children with diagnosed hearing impairment genetic tests for the C×26 35delG mutation. Objectives: The aim of the present study was to search for mutations in the GBJ2 gene among Swedish persons with non-syndromic hearing impairment to further clarify how common these mutations are in Sweden, one of the northernmost countries in Europe. Methods: Seventy-nine patients with non-syndromic hearing impairment participated in the study. For 87% of the participants, a pure tone audiogram showed a severe or profound hearing impairment. Dried blood spots on filter paper, taken at 3-5 days of age in the Swedish nationwide neonatal screening programme for congenital disorders and saved in a biobank, were used for the molecular genetic analyses. Results: The total number of subjects with one or two pathologic mutations or a mutation of unknown consequence found in the GJB2 gene was 28 of 79 (35%). Nineteen (19) persons (24%) were homozygotes for the 35delG mutation. [ABSTRACT FROM AUTHOR]

Conclusion: This universal newborn hearing-screening (UNHS) programme revealed high efficacy. The proportion of congenital sensorineural hearing loss was higher in left ears and in males than in right ears and females, which was in line with the systematic ear asymmetries and sex differences in transient-evoked otoacoustic emission (TEOAE) pass percentage. Objectives: To study the long-term outcome of a UNHS programme based on multiple TEOAEs and clinical click-evoked auditory brainstem response (ABR). Method: The study included all the newborns that were screened during a 6-year period ( n == 31 092). TEOAE pass/fail was analysed in detail. In an assessment performed 10 years after the start of the 6-year UNHS, prevalence, degree and type of congenital hearing loss were studied. Results: The proportion of screened newborns was high, i.e. 98%. Multiple TEOAE recordings minimized the need for clinical ABR. Fifty-seven (0.18%) subjects showed bilateral hearing loss (exceeding ≈≈ 30 dB HL); median ABR threshold == 60 dB nHL (at 2.5 months of age). Bilateral and unilateral sensorineural hearing loss was found in 0.17% ( n == 52; 56% males) and 0.06% ( n == 18; 61% left ears, 56% males) of the screened newborns, respectively. Higher TEOAE pass percentages ( p < 0.01) were demonstrated in right ears and in females than in left ears and males. [ABSTRACT FROM AUTHOR]

To describe the attitudes among parents towards including cystic fibrosis (CF) in the newborn screening programme and towards the potential knowledge of their own carrier status. A questionnaire with three to five response categories and an information leaflet was posted to 143 CF parents, 3 matched diabetes and 3 matched population parents, the response rate being 85%, 74% and 70%, respectively. Comparisons between groups were made with statistical tests for independent groups. Eighty-six percent of CF, 70% of diabetes and 77% of population parents were in favour of newborn screening for CF, 47%, 45% and 50%, respectively, wished to know their CF carrier status. The parental attitude was independent of the age of the child, as well as delay of diagnosis and well-being of the CF child at the time of diagnosis. Sixty percent of the CF parents experienced the diagnosis as delayed. Parents in Sweden support CF newborn screening. Half of the parents wanted to know their CF carrier status. [ABSTRACT FROM AUTHOR]

Children with cystic fibrosis (CF) diagnosed by neonatal screening have a better nutritional development and other advantages compared with those in a nonscreened group. The two-tier immunoreactive trypsinogen (IRT)/DNA screening protocol has been found superior to the single-tier IRT approach, improving the positive predictive value and thus reducing the false–positive rate. However, variations of the DNA test are required for different populations. In this study we examined CFTR (cystic fibrosis transmembrane conductance regulator) mutations in 331 CF patients attending the centres in Stockholm, Lund and Uppsala, comprising about 75% of the CF population in Sweden. The frequency of ΔF508 among CF alleles was 68.3% There were two other mutations, 394delTT and 3659delC, found to be fairly frequent, amounting to 8.5 and 7.9%, respectively. Other mutations were comparatively rare. A simple and effective method of analysing the three mutations from Guthrie cards has been developed. Assuming Hardy–Weinberg equilibrium, 90% of our CF patients will be expected to carry at least one ΔF508 allele and 97.6% to carry at least one ΔF508, 394delTT or 3659delC copy. Including the latter two in a screening programme would thus substantially reduce the risk of a false–negative outcome. [ABSTRACT FROM AUTHOR]