Genotype and clinical care correlations in craniosynostosis: findings from a cohort of 630 Australian and New Zealand patients.

Craniosynostosis is one of the most common craniofacial disorders encountered in clinical genetics practice, with an overall incidence of 1 in 2,500. Between 30% and 70% of syndromic craniosynostoses are caused by mutations in hotspots in the fibroblast growth factor receptor (FGFR) genes or in the TWIST1 gene with the difference in detection rates likely to be related to different study populations within craniofacial centers. Here we present results from molecular testing of an Australia and New Zealand cohort of 630 individuals with a diagnosis of craniosynostosis. Data were obtained by Sanger sequencing of FGFR1, FGFR2, and FGFR3 hotspot exons and the TWIST1 gene, as well as copy number detection of TWIST1. Of the 630 probands, there were 231 who had one of 80 distinct mutations (36%). Among the 80 mutations, 17 novel sequence variants were detected in three of the four genes screened. In addition to the proband cohort there were 96 individuals who underwent predictive or prenatal testing as part of family studies. Dysmorphic features consistent with the known FGFR1-3/TWIST1-associated syndromes were predictive for mutation detection. We also show a statistically significant association between splice site mutations in FGFR2 and a clinical diagnosis of Pfeiffer syndrome, more severe clinical phenotypes associated with FGFR2 exon 10 versus exon 8 mutations, and more frequent surgical procedures in the presence of a pathogenic mutation. Targeting gene hot spot areas for mutation analysis is a useful strategy to maximize the success of molecular diagnosis for individuals with craniosynostosis.

QTL mapping of complex binary traits in an advanced intercross line.

An advanced intercross line (AIL) is an easier and more cost-effective approach compared to recombinant inbred lines for fine mapping of quantitative trait loci (QTL) identified by F(2) designs. In an AIL, a complex binary trait can be mapped through analysis of either continuously distributed proxy traits for the liability of the binary trait or the liability itself, the latter presenting the greater statistical challenge. In another work, we successfully applied both approaches in an AIL to fine map previously identified QTL underlying anatomical parameters of the cardiac inter-atrial septum including patent foramen ovale. Here, we describe the statistical methods that we used to analyse complex binary traits in our AIL design. This is achieved using a likelihood-based method, with the expectation-maximisation algorithm allowing use of standard logistic regression methods for model fitting.

One set resistance training: effect on body composition in overweight young adults.

AIM: This study evaluate the impact of a 6-month, 1-set RT protocol on changes in weight and body composition in overweight young adults. METHODS: Sixty-three overweight young adults were randomized to RT or control; 55 participants (RT: N.=32; C: N.=23; BMI=27.3+2.9; age=20.7+2.7 yrs) competed the 6 month training protocol and all assessments. RT consisted of 1-set, 9 exercises, 3 times/wk., with a resistance of 3-6 repetition maximum (RM). Body composition was assessed using dual energy X-ray absorptiometry, and strength using 1RM. Participants were instructed to maintain their normal ad libitum diet and normal activities of daily living. RESULTS: Body weight and BMI increased significantly (P<0.05) in RT and C, however; the between group difference was not significant. RT induced a mean increase in fat-free mass of 1.5 kg in both males and females with significant between groups differences for change in fat-free mass noted in the total sample, and in both males and females. Between group differences for change in fat mass were not statistically significant in the total sample, or in either gender. Significant between group differences for change in % fat were noted in the total sample (RT=-0.3%, C=+5.8%, P<0.05) and in females (RT=-3.7%, C=+3.0%, P<0.01), but not in males (RT=3.4%, C=9.8%). Significant between group differences (P<0.001) were observed for change in chest (RT=45 %, C=3%) and leg press (RT=57 %, C=9%) maximal strength. CONCLUSION: A 6 month, 1-set RT program in overweight young adults increased fat-free mass and prevented increases in fat mass and % fat.

Phenotypic expansion and further characterisation of the 17q21.31 microdeletion syndrome.

BACKGROUND: The recognition of the 17q21.31 microdeletion syndrome has been facilitated by high resolution microarray technology. Recent clinical delineation of this condition emphasises a typical facial appearance, cardiac and renal defects, and speech delay in addition to intellectual disability, hypotonia and seizures. METHODS AND RESULTS: We describe 11 previously unreported patients expanding the phenotypic spectrum to include aortic root dilatation, recurrent joint subluxation, conductive hearing loss due to chronic otitis media, dental anomalies, and persistence of fetal fingertip pads. Molecular analysis of the deletions demonstrates a critical region spanning 440 kb involving either partially or wholly five genes, CRHR1, IMP5, MAPT, STH, and KIAA1267. CONCLUSION: These data have significant implications for the clinical diagnosis and management of other individuals with 17q21.31 deletions.

Variants in ACTG2 underlie a substantial number of Australasian patients with primary chronic intestinal pseudo-obstruction.

BACKGROUND: Primary chronic intestinal pseudo-obstruction (CIPO) is a rare, potentially life-threatening disorder characterized by severely impaired gastrointestinal motility. The objective of this study was to examine the contribution of ACTG2, LMOD1, MYH11, and MYLK mutations in an Australasian cohort of patients with a diagnosis of primary CIPO associated with visceral myopathy. METHODS: Pediatric and adult patients with primary CIPO and suspected visceral myopathy were recruited from across Australia and New Zealand. Sanger sequencing of the genes encoding enteric gamma-actin (ACTG2) and smooth muscle leiomodin (LMOD1) was performed on DNA from patients, and their relatives, where available. MYH11 and MYLK were screened by next-generation sequencing. KEY RESULTS: We identified heterozygous missense variants in ACTG2 in 7 of 17 families (~41%) diagnosed with CIPO and its associated conditions. We also identified a previously unpublished missense mutation (c.443C>T, p.Arg148Leu) in one family. One case presented with megacystis-microcolon-intestinal hypoperistalsis syndrome in utero with subsequent termination of pregnancy at 28 weeks' gestation. All of the substitutions identified occurred at arginine residues. No likely pathogenic variants in LMOD1, MYH11, or MYLK were identified within our cohort. CONCLUSIONS AND INFERENCES: ACTG2 mutations represent a significant underlying cause of primary CIPO with visceral myopathy and associated phenotypes in Australasian patients. Thus, ACTG2 sequencing should be considered in cases presenting with hypoperistalsis phenotypes with suspected visceral myopathy. It is likely that variants in other genes encoding enteric smooth muscle contractile proteins will contribute further to the genetic heterogeneity of hypoperistalsis phenotypes.

The occurrence of congenital heart defects in an inbred herd of pigs in Australia.

OBJECTIVE: To report on the first case of congenital heart defects in pigs in Australia. DESIGN: Retrospective analysis of case records from an inbred herd of "Westran" pigs at the University of Sydney, between January 2001 and December 2004. Detailed gross and histological examination of 15 hearts from pigs that had died or were euthanased in 2004. CASE DETAILS: The necropsy records from a population of 471 pigs that had died (106 pigs) or were euthanased for research purposes (365 pigs) were analysed and the incidence of heart defects recorded, together with basic demographic data. No attempts were made to diagnose the condition in live pigs. RESULTS: Congenital heart defects were diagnosed in 6.4% of pigs but this is likely to be an underestimate of the incidence of the deformity. Eighteen pigs died on the farm as a result of the defect, and 12 pigs were diagnosed with the defect as an incidental finding. The most common abnormality seen at necropsy was a sac-like dilatation on the right lateral surface of the right atrium. This was associated with secondary deformity and hypoplasia of the adjacent left ventricle, interventricular region and part of the right ventricle. All hearts showed atrial septal defects of varying size. CONCLUSION: This is the first reported case of congenital heart defects in pigs in Australia, and one of less than five reported cases of atrial septal defects in pigs in the world. The authors conclude that there may be an element of genetic predisposition to the malformation, since it has only been reported in this inbred line of pigs.

Prioritization of health care services. A progress report by the Oregon Health Services Commission.

The Oregon Health Services Commission is composed of a group of 11 consumers and health care professionals. It was appointed by the governor as required by the "Oregon Basic Health Services Act" to produce a prioritized list of health services ranked on the basis of their relative importance to populations served. Following actuarial analysis, the legislature will determine the extent to which the "list" of services can be funded to provide health care access for Medicaid recipients earning up to the 100th percentile of the federal poverty level. Prioritization will be based on a cost-benefit formula applied to each treatment/condition unit and assignment of each of these to a general category, which itself has been ranked on the basis of "public value."

Severe micrognathia, cleft palate, absent olfactory tract, and abnormal rib development: cerebro-costo-mandibular syndrome or a new syndrome?

We report on a family in which two sibs had apparently absent ribs and severe micrognathia on prenatal ultrasonography. The pregnancies were terminated at 19 and 12 weeks of gestation, respectively. Autopsy findings in the first fetus (19 weeks of gestation) included severe micrognathia, a U-shaped defect of the soft palate, marked postnuchal edema, absent olfactory bulbs, and cribriform plate and rib abnormalities. The ribs consisted of cartilage anteriorly, with only a small amount of fibrous tissue present laterally and posteriorly. The second fetus (12 weeks gestation) had agnathia, with a large U-shaped defect in the soft palate. There was moderate postnuchal edema. The ribs were unossified and there were gaps in the cartilage where primitive mesenchyme was present posteriorly and laterally. These findings are consistent with a severe form of cerebro-costo-mandibular syndrome. The early fetal histopathology of both cases suggests a possible mechanism by which the characteristic "rib gaps" of cerebro-costo-mandibular syndrome may develop, with evidence for abnormal function of a gene or genes involved in regulation of rib chondrogenesis.

X-linked adrenoleukodystrophy: the Australasian experience.

Our objective was to review the Australasian experience of X-linked adrenoleukodystrophy (ALD), to compare the spectrum of disease seen in Australasia with previously published data from elsewhere, and to assess the reliability of carrier testing. Study design was a retrospective review of records collected over a 15-year period, the setting was an international referral laboratory for the study of metabolic disease, and the subjects were all known cases of ALD diagnosed in Australia and New Zealand between 1981 and 1996 and their families. We estimate that the combined incidence of ALD and its variants in Australasia is at least 1.6 per 100,000. Of 95 affected males, 51 had cerebral adrenoleukodystrophy, 24 had adrenomyeloneuropathy, 15 had Addison's disease only, and 5 remained asymptomatic when last examined. However, the distribution of phenotypes among newly diagnosed patients has changed substantially over the last 15 years, with cerebral forms of the disease forming a decreasing proportion of new diagnoses. The measurement of plasma very long chain fatty acids (VLCFAs) alone detects 93% of women who can be proven to be carriers. The addition of genetic linkage studies or assay of VLCFAs in cultured fibroblasts improved this detection rate to the point that there were no obligate carriers who could not be detected using a combination of two or more techniques.

The relationships among working memory, math anxiety, and performance.

Individuals with high math anxiety demonstrated smaller working memory spans, especially when assessed with a computation-based span task. This reduced working memory capacity led to a pronounced increase in reaction time and errors when mental addition was performed concurrently with a memory load task. The effects of the reduction also generalized to a working memory-intensive transformation task. Overall, the results demonstrated that an individual difference variable, math anxiety, affects on-line performance in math-related tasks and that this effect is a transitory disruption of working memory. The authors consider a possible mechanism underlying this effect--disruption of central executive processes--and suggest that individual difference variables like math anxiety deserve greater empirical attention, especially on assessments of working memory capacity and functioning.

Pregnancy after metroplasty for uterine anomalies.

OBJECTIVE: To clarify the relation between metroplasty for correction of uterine anomalies and subsequent pregnancy, we reviewed the charts of all patients for whom a diagnosis of bicornuate, septate, or didelphic uterus had been made between 1972 and 1982 and analyzed their obstetric outcomes. DESIGN: Of the 146 patients evaluated, 23 received a metroplasty procedure, and 123 patients did not have surgical intervention. Fifteen of the nonsurgical patients could be matched with 15 of the surgical patients by age, chief complaint, gravidity, and type of anomaly and therefore served as matched controls. RESULTS: The percentage of patients with living children after the diagnosis of uterine anomaly was 67% for the matched nonsurgical group and 73% for the patients who underwent metroplasty. The difference was not statistically significant. Although marked improvement in fetal salvage rates was noted when reproductive outcomes before and after metroplasty were compared, the obstetric outcome was similar to that of the control groups after the diagnosis was made and surgery deferred. CONCLUSION: The efficacy of metroplasty in the treatment of multiple pregnancy losses is thus being questioned.

Telling stories: the perils and promise of using verbal reports to study math strategies.

The problem size effect in adult arithmetic performance is generally attributed to direct retrieval processes operating on a network representation in long-term memory. J. LeFevre and her colleagues (J. LeFevre, J. Bisanz, et al., 1996; J. LeFevre, G. S. Sadesky, & J. Bisanz, 1996) challenged this explanation using verbal report evidence that adults also use time consuming nonretrieval strategies to solve simple addition and multiplication. The authors replicated J. LeFevre and colleagues' methods, but added instructional biasing and silent control conditions to test these methods. Both reaction time and report results suggest that LeFevre and colleagues' conclusions about nonretrieval frequency may have been influenced by instructions that revealed the experimental hypothesis and affected participants' strategy reports. Obtaining evidence about adult strategy use in simple arithmetic will require understanding instructional demand and appropriate report methodology.

Dominant inheritance of cleft palate with minor abnormalities of hands and feet: a new syndrome?

We report a family in which four members of three generations are affected by median cleft palate. The proband and her mother have additional features including bilateral single transverse palmar creases, broad great toes and hypoplastic fifth toenails. Dominant isolated cleft palate has rarely been reported, and there are no previous reports of dominant cleft palate with these associated features. We believe that this represents a previously unreported syndrome, which needs to be considered when assessing recurrence risk for cleft palate.

Dominant inheritance of cleft palate, microstomia and micrognathia--possible linkage to the fragile site at 16q22 (FRA16B).

We report a family in which a father and his three children are affected with microstomia, micrognathia and partial or complete cleft of the hard and soft palate. The probands were non-identical twins, a boy and a girl, both noted to have the above features soon after birth. Their father was diagnosed with a submucous cleft of the palate at the age of 4 years and their older brother has milder facial features and a bifid uvula. All affected family members were demonstrated to have a fragile site on chromosome 16q22 but otherwise normal karyotypes. Of interest is a previously described family with autosomal dominant inheritance of U-shaped cleft palate, microstomia, micrognathia and oligodontia where all affected members were shown to have the fragile site at 16q22 in a proportion of their cells [Bettex et al. (1998) Eur J Pediatr Surg 8:4-8]. We propose that these two conditions are the same and represent a distinctive syndrome involving aberrant orofacial development that may be linked to the fragile site at 16q22.

Periventricular heterotopia in common microdeletion syndromes.

Periventricular heterotopia (PH) is a brain malformation characterised by heterotopic nodules of neurons lining the walls of the cerebral ventricles. Mutations in FLNA account for 20-24% of instances but a majority have no identifiable genetic aetiology. Often the co-occurrence of PH with a chromosomal anomaly is used to infer a new locus for a Mendelian form of PH. This study reports four PH patients with three different microdeletion syndromes, each characterised by high-resolution genomic microarray. In three patients the deletions at 1p36 and 22q11 are conventional in size, whilst a fourth child had a deletion at 7q11.23 that was larger in extent than is typically seen in Williams syndrome. Although some instances of PH associated with chromosomal deletions could be attributed to the unmasking of a recessive allele or be indicative of more prevalent subclinical migrational anomalies, the rarity of PH in these three microdeletion syndromes and the description of other non-recurrent chromosomal defects do suggest that PH may be a manifestation of multiple different forms of chromosomal imbalance. In many, but possibly not all, instances the co-occurrence of PH with a chromosomal deletion is not necessarily indicative of uncharacterised underlying monogenic loci for this particular neuronal migrational anomaly.

Pulmonary haemorrhage and cardiac dysfunction in a neonate with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency.

UNLABELLED: We report on a favourable case of MCAD deficiency (homozygous 985A > G) that presented as lethargy, poor feeding, pulmonary haemorrhage and cardiac arrest without hypoglycaemia. The cessation of intralipid and the commencement of carnitine supplementation were associated with a rapid clinical improvement. CONCLUSION: Mild carnitine depletion and secondary impairment of long-chain fatty acid metabolism may have contributed to post-asphyxial myocardial dysfunction and ventricular arrhythmias. Metabolic disorders must be kept in mind as a differential diagnosis in acutely ill infants, but it must also be emphasized that carnitine therapy is not uniformly effective in all MCAD patients.