Diagnosing Hunter syndrome in pediatric practice: practical considerations and common pitfalls

Mucopolysaccharidosis II (MPS II), or Hunter syndrome, is an X-linked lysosomal storage disorder caused by a deficiency in the enzyme iduronate-2-sulfatase. Affected patients suffer progressive damage to multiple organ systems and early mortality. Two thirds of patients also manifest cognitive impairment and developmental delays. MPS II can be extremely difficult to diagnose before irreversible organ and tissue damage has occurred because of an insidious onset and the overlap in signs and symptoms with common childhood complaints. This is particularly true of patients without cognitive impairment (attenuated phenotype). Although not curative, early treatment with enzyme replacement therapy before irreversible organ damage has occurred may result in the greatest clinical benefit. Here, the signs, symptoms, and surgical history that should trigger suspicion of MPS II are described, and the diagnostic process is reviewed with a focus on practical considerations and the avoidance of common diagnostic pitfalls. Once a diagnosis is made, multidisciplinary management with an extended team of pediatric specialists is essential and should involve the pediatrician or family practice physician as facilitator and medical home for the patient and family. Conclusion: Because routine newborn screening is not yet available for MPS II, the involvement and awareness of pediatricians, family practice physicians, and pediatric specialists is critical for early identification, diagnosis, and referral in order to help optimize patient outcomes

Strength training and low back pain

BACKGROUND: Resistance to thyroid hormone is characterised by a lack of response of peripheral tissues to the active form of thyroid hormone (triiodothyronine, T3). In about 85% of cases, a mutation in THRB, the gene coding for thyroid receptor beta (TRbeta), is the cause of this disorder. Recently, individual reports described the first patients with thyroid hormone receptor alpha gene (THRA) defects. METHODS: We used longitudinal clinical assessments over a period of 18 years at one hospital setting combined with biochemical and molecular studies to characterise a novel thyroid hormone resistance syndrome in a cohort of six patients from five families. FINDINGS: Using whole exome sequencing and subsequent Sanger sequencing, we identified truncating and missense mutations in the THRA gene in five of six individuals and describe a distinct and consistent phenotype of mild hypothyroidism (growth retardation, relatively high birth length and weight, mild-to-moderate mental retardation, mild skeletal dysplasia and constipation), specific facial features (round, somewhat coarse and flat face) and macrocephaly. Laboratory investigations revealed anaemia and slightly elevated cholesterol, while the thyroid profile showed low free thyroxine (fT4) levels coupled with high free T3 (fT3), leading to an altered T4 : T3 ratio, along with normal thyroid-stimulating hormone levels. We observed a genotype-phenotype correlation, with milder outcomes for missense mutations and more severe phenotypical effects for truncating mutations. INTERPRETATION: THRA mutations may be more common than expected. In patients with clinical symptoms of mild hypothyreosis without confirmation in endocrine studies, a molecular study of THRA defects is strongly recommended

Study of time as being according to the Keraakie people of Southwest Papua New Guinea

BACKGROUND: Mucopolysaccharidosis III (MPS III), known as Sanfilippo disease, is a lysosomal storage disorder mainly characterized by progressive neurodegeneration with cognitive decline and relatively attenuated somatic signs and symptoms. Although short stature is invariably present in patients with the other mucopolysaccharidoses, it has not been sufficiently addressed in MPS III. The aim of this study was to investigate growth data of a large Dutch MPS III cohort in order to construct growth charts for MPS III patients. METHODS: Height, weight, head circumference (HC), and body mass index (BMI) data from 118 MPS III patients were used to construct reference curves, using the lambda, mu, sigma (LMS) method. Genotype-group comparisons for height standard deviation scores (SDS) were performed by Kruskal-Wallis analysis for different age groups. RESULTS: Birth weight and length were within normal ranges for gestational age and showed a significantly stunted growth from age 6 years onward. Mean final heights were 169.7 cm (-2.0 SDS) and 165.4 cm (-0.84 SDS) for adult male and female, patients, respectively. Phenotypic severity, as assessed by genotyping, correlated with growth pattern and final height. In addition, mean BMI and HC SDS were significantly higher when compared with Dutch standards for both boys and girls. CONCLUSIONS: Growth in MPS III is stunted mainly in patients with the severe phenotype. We provide disease-specific growth references that can be used for clinical management of MPS III patients and may be of value for future treatment studies