Hypothyroid Myopathy-A Rare Case from Paediatric Practice

Hypothyroid myopathy is uncommon in childhood. Severe hypothyroid myopathy observed in paediatric practice is a part of Kocher-Debré-Semelaigne syndrome (KDSS, OR-PHA:2349), a rare disorder characterised by muscular pseudohypertrophy and long-standing moderate-to-severe hypothyroidism. We present a pubertal girl with KDSS diagnosed with severe myopathy and significantly limited mobility and progressively increasing pains in the lumbar area, hip joints, and the lower limbs. Additionally, the patient presented metabolic syndrome with severe obesity, growth retardation, and educational difficulties. In this case, adequate hormone replacement therapy with Levothyroxine evoked full recovery of the myopathy and a significant reversal in the patient's general condition. In conclusion, emphasizing the knowledge related to KDSS can improve the diagnosis and prognosis of the condition.

Clinical presentation and treatment response to diazoxide in two siblings with congenital hyperinsulinism as a result of a novel compound heterozygous ABCC8 missense mutation

BACKGROUND

Congenital hyperinsulinism (CHI) can present with considerable clinical heterogeneity which may be due to differences in the underlying genetic etiology. We present two siblings with hyperinsulinaemic hypoglycaemia (HH) and marked clinical heterogeneity caused by compound heterozygosity for the same two novel ABCC8 mutations.

CASE PRESENTATION

The index patient is a 3-year-old boy with hypoglycaemic episodes presenting on the first day of life. HH was diagnosed and treatment with intravenous glucose and diazoxide was initiated. Currently he has normal physical and neurological development, with occasional hypoglycaemic episodes detected following continuous fasting on treatment with diazoxide. The first-born 8-year-old sibling experienced severe postnatal hypoglycaemia, generalised seizures and severe brain damage despite diazoxide treatment. The latter was stopped at 6-months of age with no further registered hypoglycaemia. Genetic testing showed that both children were compound heterozygotes for two novel ABCC8 missense mutations p.I60N (c.179T>A) and p.G1555V (c.4664G>T).

CONCLUSIONS

These ABCC8 missense mutations warrant further studies mainly because of the variable clinical presentation and treatment response.

Abnormal levels of serum antielastin antibodies in children with diabetes mellitus type 1

Antibodies to alpha-elastin (elastin breakdown product) and elastin sequences devoid of cross-linked regions (linear elastin) are found in the serum of all human subjects and correlate with their respective serum peptide levels. The aim of this study was to determine if the serum level of antielastin antibodies (AEAbs) differs between type 1 diabetic children and nondiabetic children. Enzyme-linked immunosorbent assay was used to measure the levels of immunoglobulin (Ig)G and IgM AEAbs in the sera of 45 diabetic children (mean age 12.8 +/- 3.2 years, diabetes duration 5.3 +/- 3.6 years). Twenty-two children presented with vascular complications (group 1), whereas 23 displayed no vascular complications (group 2). The controls were 18 healthy children (mean age 11.9 +/- 2.3 years). Diabetic patients showed statistically significant higher levels of IgM alpha-AEAbs (0.82 +/- 0.26 vs 0.61 +/- 0.14, p = .0013) than the control group. In group 1, alpha-AEAbs showed statistically significant higher level than controls: IgG (0.86 +/- 0.42 vs 0.59 +/- 0.12; p = .0109) and IgM (0.88 +/- 0.24 vs 0.61 +/- 0.14; p = .0001). IgM antilinear elastin antibodies (ALEAbs) in group 1 were significantly lower than in controls (0.462 +/- 0.191 vs 0.652 +/- 0.127; p = .0009). IgG alpha-AEAbs showed correlation with microalbuminuria (r = -.26; p = .05) and IgM ALEAbs correlated with microalbuminuria (r = -.32; p = .035). IgG alpha-AEAbs correlated with neuropathy (r = -.32; p = .035). Group 1 patients displayed a correlation between IgG ALEAbs and retinopathy (r = -.48; p = .023) and IgM ALEAbs and microalbuminuria (r = .52; p = .014). Levels of AEAbs and ALEAbs can serve as immunologic markers of the extent of elastin degradation. These markers may provide a tool to study elastin metabolism and a potential clinical role for AEAbs in the pathogenesis and development of vascular complications in diabetic children.

Detection of serum collagen type IV in children with type 1 (insulin-dependent) diabetes mellitus--a longitudinal study

The basement membrane is a major focus of scientific interest because of its role in a variety of diseases. In diabetes mellitus, a thickening of the capillary basement membrane results in microangiopathic lesions. To monitor the metabolism of the basement membrane protein collagen type IV (CIV) in diabetes mellitus, serum levels of CIV were measured using an enzyme-linked immunosorbent assay (ELISA) method in 28 children with type 1 diabetes mellitus over a period of 6 years. These values were compared to serum CIV levels in 24 age and sex matched controls. In the first 3 years, serum CIV levels were normal. In the 4th year, 1 patient and in years 5 and 6, 4 patients had increased CIV serum levels. At the end of the investigation, 3 children had developed retinopathy, 6 microalbuminuria, and 2 both microalbuminuria and retinopathy. Only those patients with microalbuminuria had increased CIV serum levels. In conclusion, we suggest that CIV serum levels can be used as a marker for the development of diabetic microalbuminuria.

Relationship between elastin-derived peptides and the development of microvascular complications: a longitudinal study in children with Type 1 (insulin-dependent) diabetes mellitus

Levels of elastin-derived peptides (EDP) were determined by enzyme-linked immunosorbent assay (ELISA) in sera of 28 children with Type 1 (insulin-dependent) diabetes mellitus (mean age 11.6+/-2.8 years, diabetes duration 5.1+/-2.5 years). None of the children had clinical or laboratory evidence of vascular complications. The children were followed over a period of 6 years, and 24 healthy children of similar age and sex served as a control group. During the investigative period, 10 diabetic patients had increased EDP levels, with 9 having been diabetic for more than 5 years and 1 patient less than 5 years. Seven of these patients developed diabetic microvascular complications. In this group, EDP were independently associated with age (r=.39, P=.047), retinopathy (r=.48, P=.034), and antibodies to advanced glycation endproducts (AGE) (r=.52, P=.018). The data of this pilot study are not strong enough to appear that EDP are a useful predictor of subsequent development of microvascular complications. This may be due to the small number of subjects, short duration of the study, manner in which EDP or the endpoints were measured, or frequency of which EDP measurements were made. Further prospective and longer studies of larger populations are needed to identify the role of EDP as an early marker for the development of diabetic microvascular complications.

An association of anti-elastin IgA antibodies with development of retinopathy in diabetic children

An important factor in the development of vascular wall alterations is degradation of the elastic fiber major protein-elastin. Elastin peptides derived from this degradation are present in the circulating blood and they are a stimulus for increased production of anti-elastin antibodies (AEAb). The aim of the present study was to examine the possible association between serum elastin AEAb and the development of diabetic vascular complications. Levels of AEAb (IgG, IgM and IgA) were determined by ELISA in sera of 28 children with Type 1 (insulin-dependent) diabetes mellitus (mean age 11.6+/-2.8 years, diabetes duration 5.1+/-2.5 years). None of the children had clinical or laboratory evidence of vascular complications. The children were followed over a period of 7 years, and 24 healthy children of similar age and sex served as a control group. During the study, four diabetics developed retinopathy, six microalbuminuria and two both retinopathy and microalbuminuria. Anti-elastin IgG showed correlation with diabetes duration (r=.48, P=.0007), HbA1c (r=.28, P=.05), triglycerides (r=.28, P=.05) and antibodies to advanced glycation endproducts (AGE) (r=.41, P=.005). Anti-elastin IgM correlated with HbA1c (r=.26, P=.038) and IgA with retinopathy (r=.32, P=.017). Our results suggest an association between the level of anti-elastin IgA antibodies and the development of diabetic retinopathy.