The reported incidence rate of primary congenital hypothyroidism (CH) has been increasing in the United States over the past 2 decades. We have considered the possibility that the inclusion of cases of transient hypothyroidism has inflated the reported incidence rate of CH. Assessing the effects of cases of transient hypothyroidism on the incidence rate is problematic, because the definitions, ...

Two manifestations of hybrid dysgenesis were studied in flies with chromosomes derived from two different P strains. In one set of experiments, the occurrence of recessive X-linked lethal mutations in the germ cells of dysgenic males was monitored. In the other, the behavior of an X-linked P-element insertion mutation, snw, was studied in dysgenic males and also in dysgenic females. The chromos...

In plants and mammals, small RNAs indirectly mediate epigenetic inheritance by specifying cytosine methylation. We found that small RNAs themselves serve as vectors for epigenetic information. Crosses between Drosophila strains that differ in the presence of a particular transposon can produce sterile progeny, a phenomenon called hybrid dysgenesis. This phenotype manifests itself only if the tr...

Mosaicism introduces wide variability into the clinical expression of numerical and unbalanced structural chromosomal abnormalities. The phenotypic range of variability of 45,X/46,XY mosaicism extends from Turner syndrome to mixed gonadal dysgenesis to normal males. The specific phenotype is primarily dependent on the chromosomal constitution of the developing gonad. Similar phenotypic variabil...

The telomeric P elements TP5 and TP6 are associated with the P cytotype, a maternally inherited condition that represses P-element-induced hybrid dysgenesis in the Drosophila germ line. To see if cytotype repression by TP5 and TP6 might be mediated by the polypeptides they could encode, hobo transgenes carrying these elements were tested for expression of mRNA in the female germ line and for re...

Steroidogenic factor 1 (SF1, NR5A1) is a nuclear receptor that regulates multiple genes involved in adrenal and gonadal development, steroidogenesis, and the reproductive axis. Human mutations in SF1 were initially found in two 46,XY female patients with severe gonadal dysgenesis and primary adrenal failure. However, more recent case reports have suggested that heterozygous mutations in SF1 may...

Synaptosomal-associated protein 29 (SNAP29) is a t-SNARE protein that is implicated in intracellular vesicle fusion. Mutations in the SNAP29 gene have been associated with cerebral dysgenesis, neuropathy, ichthyosis, and keratoderma syndrome (CEDNIK). In patients with 22q11.2 deletion syndrome, mutations in SNAP29 on the nondeleted chromosome are linked to similar ichthyotic and neurological ph...

Deletions of distal chromosome 9p24 are often associated with 46,XY gonadal dysgenesis and, depending on the extent of the deletion, the monosomy 9p syndrome. We have previously noted that some cases of 46,XY gonadal dysgenesis carry a 9p deletion and exhibit behavioural problems consistent with autistic spectrum disorder. These cases had a small terminal deletion of 9p with limited or no somat...

Purpose The purpose of this study was to comparatively evaluate angle dysgenesis in vivo, among congenital, juvenile, and adult-onset open angle glaucoma patients. Methods A cross-sectional evaluation of 96 glaucoma patients, 22 children with primary congenital glaucoma (PCG) old enough to cooperate for optical coherence tomography (OCT), 34 juvenile-onset open angle glaucoma (JOAG) patients,...

Hybrid dysgenesis in Drosophila is a syndrome of gonadal atrophy, sterility, and male recombination, and it occurs in the progeny of crosses between males that harbor certain transposable elements (TEs) and females that lack them. Known examples of hybrid dysgenesis in Drosophila melanogaster result from mobilization of individual families of TEs, such as the P element, the I element, or hobo. ...