Selective IgA deficiency, hypothyroidism and congenital lymphoedema

Undetectable serum IgA and low IgM concentration in children with congenital hypothyroidism

Some studies suggest thyroid hormones may regulate the human immune system. In order to evaluate the effect of thyroid hormone deficiency on antibody production, we evaluated serum IgA and IgM concentrations in 83 children with congenital hypothyroidism (CH), diagnosed by neonatal screening. Patients were compared to two healthy, age-matched control groups. Patients with permanent CH had a significantly higher frequency of undetectable IgA concentrations (thyroid agenesis, P<10(-5); thyroid ectopy, P=0.013) and lower concentrations of IgA (thyroid agenesis, P<10(-6); thyroid ectopy, P<10(-5); dyshormonogenesis, P=0.0002) and IgM (thyroid agenesis, P=0.0002; thyroid ectopy, P<10(-6); dyshormonogenesis, P=0.0017) compared to control group. No difference was observed between patients with transient hypothyroidism and controls. A significant correlation was observed between serum IgA and IgM concentrations and fT4 levels. IgA and IgM deficiency is correlated with the severity of congenital hypothyroidism and may help to evaluate the duration and severity of thyroid hormone deficiency during prenatal life.

Turner's syndrome in dermatology

Turner's syndrome (TS) is a common genetic disorder of girls and women, for which the defining clinical triad is short stature, impaired sexual development, and infertility. Although classically known as monosomy X, genetic heterogeneity is frequent in TS, with mosaicism conferring a survival advantage. Several genetic loci have been implicated in TS including the short stature homeobox gene. TS effects many organs, with cutaneous stigmata providing critical clues for early detection of TS. The presence of lymphedema and its cutaneous sequelae are predictive of other systemic disorders, such as cardiac disease. Although an increased number of benign nevi have been reported in TS, the decreased melanoma rate in this population suggests some protective factor is active. Keloids were thought to be prevalent in TS, but recent data suggest otherwise. Autoimmune diseases are common in TS, with a possible increased prevalence of alopecia areata and vitiligo. The following review discusses new insights into the genetics and pathogenesis of this complex disorder, summarizes the major systemic effects, and reviews skin manifestations of TS and their implications.

Mapping of primary congenital lymphedema to the 5q35.3 region

Primary lymphedema is a chronic tissue swelling, most frequently of the lower limbs, resulting from deficient lymphatic drainage. The variability of the affected phenotype, incomplete penetrance, lack of large families, and possible genetic heterogeneity have hampered the identification of causative genes until now. We carried out a genomewide search, using a four-generation North American family with dominantly inherited primary congenital lymphedema (PCL), otherwise known as "Milroy disease," or "hereditary lymphedema type I" (MIM 153100). Linkage to markers from the 5q35.3 region in this and four additional, British families was established. A minimum of 79 directly scorable haplotypes (37 affected) in five families conspicuously segregated with the most telomeric region of 5q35.3, thus suggesting a major locus for PCL in this vicinity. No recombination was observed with D5S408 (Z = 10.03) and D5S2006 (Z = 8.46) with a combined multipoint score of 16.55. While D5S2073 and WIAF-2213 defined the upper centromeric boundary, no recombinants were obtained for the last telomeric marker of D5S2006. Four unaffected subjects were identified as gene carriers and provided an estimated penetrance ratio of.84 for this condition. A few of the positionally mapped genes in the 5q35 region that may potentially be involved in the etiology of this condition are CANX, FGFR4, HK3, and hnRPH1.