Neural systems approaches to the neurogenetics of autism spectrum disorders

Autism is generally accepted as the most genetic of all the developmental neuropsychiatric syndromes. However, despite more than several decades of genetic study, the etiology of autism remains unknown, largely due to the genetic and phenotypic diversity, or heterogeneity, of this disorder, and the lack of biologically based classification systems. At the same time, in the neuroimaging literature, the body of research identifying candidate neural systems underlying aspects of autistic impairment has grown considerably, fueled by the advent of technologies such as functional magnetic resonance imaging (fMRI). Yet the findings from these neuroimaging studies have not been incorporated to inform the collection of samples for genetic studies of autism, which are predominantly based on a diagnosis of the disorder. This article presents a review of the genetics of autism and describes the genetic approaches that have been applied, including the phenotypic strategies that have been used to address heterogeneity and optimize the power of these genetic studies. With the increasing recognition that there may be different "autisms" (Geschwind and Levitt, 2007) with unique neural mechanisms, it is argued that neural systems research, using technologies such as fMRI, currently allows for the identification of more biologically informative phenotypes for genetic studies of autism and is positioned to identify informative neuroimaging markers for "neurogenetic" studies of the disorder. To illustrate this, we describe several candidate neural systems for the social communication impairment seen in autism, and the characteristic behavioral and physiological manifestations associated with these that could be incorporated into phenotypic assessments.

Glomerular diseases in children. "The Iranian experience"

A total of 411 children, aged from 0.3 to 18 years, suffering from glomerular diseases, were studied by renal biopsy between 1976 and 1985. The clinical presentation included nephrotic syndrome (79% of cases), renal failure (43%), and arterial hypertension (38%). In all, 177 cases presented with primary nephrotic syndrome; all had complicated courses and most were either corticosteroid-dependent or -resistant. Only 26.6% had minimal change disease on renal biopsy; 56.5% had focal-segmental sclerosis; and immunofluorescent deposits were observed in half of the group. Acute poststreptococcal (36 cases), mesangiocapillary (80 cases), and lupus (34 cases) glomerulonephritis occurred frequently; IgA glomerulopathy (10 cases) and haemolytic uraemic syndrome (6 cases) were uncommon. Glomerular crescents were observed in 71 cases. These observations illustrate the types of glomerular diseases seen in Iranian children.

Primary nephrotic syndrome in Iran: clinicopathological study of 310 cases

Three hundred and ten children with primary nephrotic syndrome were studied since 1972. 190 patients are classified as nephrosis (61%); including minimal glomerular lesions (22.9%), diffuse mesangial proliferation (6.77%) and focal and segmental sclerosis (31.6%). Corticoresponsivity was limited: 53.75% with a higher success rate in minimal glomerular lesions: 74% versus 38% of diffuse mesangial proliferation and 42.5% focal and segmental sclerosis. Immunosuppressive drugs were used for 96 patients corticodependent or resistant. They were more effective in dependent than resistant cases 94% versus 38%. A total of 149 cases were followed (mean: 3.9 years). In the last evaluation 67% were in remission, 8.10% in chronic renal failure and 24.8% with other abnormalities.

Cardiac aspect of Cooley's anemia

The short- and long-term effect of multiple versus regularly spaced blood transfusions on cardiac size, electrocardiographic alterations, heart sounds, murmurs, and carotid pulse were studied in 18 children with Cooley's anemia. These parameters were evaluated before transfusions, one week after multiple blood transfusions (when hemoglobin levels had reached normal), and during the following year, when conventionally spaced transfusions were given. Results showed that enlarged hearts may regress to normal size after multiple transfusions. Chamber hypertrophies and second heart sound were inconstant, and the average of all mean QRS and T vectors was not altered significantly after transfusions. There was good correlation between hemoglobin levels and tachycardia, intensity of first heart sound, heart murmurs, and ejection systolic clicks. Upstroke time of carotid pulse increased with restoration of normal hemoglobin levels. It is concluded that patients maintained at a higher hemoglobin level are generally in better cardiovascular status.