Prevalence of Angelman syndrome and Prader-Willi syndrome in Estonian children: sister syndromes not equally represented

In 2000-2004, we performed a focused search for individuals with Angelman syndrome (AS) and Prader-Willi syndrome (PWS) aiming to establish the prevalence data for the individuals born between 1984 and 2004 in Estonia. All persons with probable AS or PWS (n = 184) were studied using the DNA methylation test. Individuals with abnormal methylation were all further tested by chromosomal and FISH analysis, and if necessary for uniparental disomy and UBE3A gene mutation. Nineteen cases with abnormal methylation test result were identified. Seven of them had AS, including six (85.7%) due to 15q11-13 deletion and one paternal UPD15. Twelve subjects had PWS: 4 (33%) 15q11-13 deletions, 6 (50%) maternal UPD15, 1 unbalanced chromosome 14;15 translocation resulting in a chromosome 15pter-q13 deletion, and 1 Robertsonian 15q;15q translocation. The minimum livebirth prevalence in 1984-2004 for AS was 1:52,181 (95% CI 1:25,326-1:1,29,785) and for PWS 1:30,439 (95% CI 1:17,425-1:58,908). The livebirth prevalence of AS and PWS increased within this period, but the change was statistically significant only for PWS (P = 0.032), from expected 1:88,495 (95% CI 1:24,390-1:3,22,580) to expected 1:12,547 (95% CI 1:540-1:29,154). Six individuals with AS and 11 with PWS were alive on the prevalence day (January 1, 2005), indicating the point prevalence proportion of 1:56,112 (95% CI 1:25,780-1:1,52,899) and 1:30,606 (95% CI 1:17,105-1:61,311), respectively. Our results showing the birth prevalence of AS 1.7 times less than PWS challenge the opinion that both syndromes are equally represented, and are in line with the view that mutations in sperm and oocytes occur at different frequencies.     

Validation of the Finnish Autism Spectrum Screening Questionnaire (ASSQ) for Clinical Settings and Total Population Screening

We assessed the validity and determined cut-off scores for the Finnish Autism Spectrum Screening Questionnaire (ASSQ). A population sample of 8-year-old children (n?=?4,408) was rated via the ASSQ by parents and/or teachers, and a subgroup of 104 children was examined via structured interview, semi-structured observation, IQ measurement, school observation, and medical records. Autism spectrum disorders (ASDs) were diagnosed following DSM-IV-TR criteria. A search for hospital-registered ASDs was performed. For Finnish higher-functioning primary school-aged, 7- to 12-year-olds, the optimal cut-off score was 30 in clinical settings and 28 in total population screening using summed ASSQ scores of parents' and teachers' ratings. Determining appropriate cut-off scores in ASD screening in different languages and in different cultures is of utmost importance.     

Cephalometric pharyngeal changes after Le Fort I osteotomy in different types of clefts.

Fifty patients with clefts (30 unilateral cleft lip and palate (UCLP), 9 bilateral cleft lip and palate (BCLP), and 11 cleft palate only (CP), mean age 25 years) treated with Le Fort I osteotomy were compared retrospectively from cephalograms taken shortly before operation, and at six months and one year postoperatively. Patients with bimaxillary surgery or previous velopharyngoplasty, or both, were excluded. Maxillary advancement was moderate in all groups. One year postoperatively there was a significant change (73%-90% of the surgical advancement) in the sagittal depth of the nasopharyngeal airway but not in the depth of the oropharyngeal airway, the length of the soft palate or the position of the hyoid bone. The nasopharyngeal airway was largest in the CP group both preoperatively and postoperatively. Eleven patients (7 CP, 4 UCLP) had a velopharyngoplasty after the osteotomy to improve their speech. There was no difference in the nasopharyngeal airway in the patients treated by velopharyngoplasty compared with those not so treated, but they seemed to have the shortest maxillas and the greatest surgical changes vertically.