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An intermediate phenotype of a disease is a trait in the path of pathogenesis from genetic predisposition to disease manifestation. Identifying intermediate phenotypes with high heritability is helpful in delineating the genetics of a disorder. In this study, we aimed to examine various traits with regards to obesity, cardiovascular risk and upper airway structure to identify potential intermediate phenotypes of childhood obstructive sleep apnea (OSA). Children aged between 6 and 18 years and their parents and siblings were recruited. All subjects underwent anthropometric measurements, cardiovascular risk assessment, sonographic measurement of lateral parapharyngeal wall (LPW) thickness, X‐ray cephalometry and overnight polysomnography. A total of 34 phenotypes were examined. One hundred and one families consisting of 127 children (46 overweight) and 198 adults (84 overweight) were recruited. Heritability of obstructive apnea–hypopnea index (OAHI) was significant in overweight (h2 = 0.54) but not normal‐weight individuals (h2 = 0.12). LPW thickness (h2 = 0.68) and resting blood pressure (h2 = 0.36 and 0.43 for systolic blood pressure [SBP] and diastolic blood pressure [DBP], respectively) were significantly heritable and associated with OAHI. Moreover, these traits were found to have shared genetic variance with OAHI in the overweight subgroup. Hyoid bone position also had significant heritability (h2 = 0.55) and association with OAHI but genetic correlation with OSA severity was not demonstrated. These findings suggest that LPW thickness and resting blood pressure are possible intermediate phenotypes of OSA independent of body mass index, especially in overweight patients. Identifying genes relevant to these phenotypes may help to elucidate the genetic susceptibility of OSA. [ABSTRACT FROM AUTHOR]

BACKGROUND: Obstructive sleep apnea (OSA) affects both adults and children, likely mediated by the deficits of various brain regions. The association between structural alterations in the brain and OSA syndrome have been reported in adult patients, but the corresponding evidence for OSA children is still limited. OBJECTIVE: The proposed study aimed to investigate the structural alterations in the brain of children with OSA, with focus on basal ganglia structures. METHODS: We recruited 25 OSA children (aged 10.3±1.5 years) and 30 healthy children (aged 10.1±1.8 years) with T1-weighted brain MRI and performed automatic segmentation of their brains. The shape alterations of the basal ganglia structures for OSA syndrome was determined by comparison of the OSA group and control group with surface-based shape analysis. RESULTS: Differences in the morphometry of the left thalamus and the left pallidum were found between the OSA group and control group. Compared to the control group, the OSA group presented significant atrophy in the ventral posterior nucleus and the medial dorsal nucleus of the left thalamus, while regional dilation was found in both the internal and external segments of the left pallidum. CONCLUSION: These findings identified the association between the structural deficits of the thalamus and OSA syndrome in children, which was consistent with the existing findings in OSA adults. In addition, the present study provided new insights to the distinctive pattern of structural changes of the pallidum in pediatric OSA when compared to adult OSA. [ABSTRACT FROM AUTHOR]

The article reports on the results of research which was conducted in an effort to investigate the renal outcomes of children in Hong Kong, China that had been exposed to low doses of melamine. Researchers evaluated 3,170 children who had been referred to primary care clinics after having had consumed milk products tainted with melamine on a daily basis for a month or more. Researchers found no severe adverse renal outcomes in the children but did find the presence of renal stones and hematuria. They also found that large scale screening programs which have been set up may not be informative or cost effective for populations that have been exposed to low dose melamine.

This paper is a comprehensive review of the Doppler waveform appearance of ureteric jets. Six jet waveform patterns have been identified: monophasic, biphasic, triphasic, polyphasic, square and continuous. Details of the physical properties of jet patterns and their changes under various physiological conditions are illustrated. The immature monophasic ureteric jet pattern is common in infancy and early childhood up to around 4 years of age. This pattern is also noted to have a high incidence in older children with urinary tract infection/vesicoureteric reflux, nocturnal enuresis and in other special physiological conditions such as in children undergoing general anaesthesia, in women during pregnancy, and in patients who have had ureteric transplantation. A hypothesis of dual myogenic and neurogenic components is proposed to explain the mode of action of the vesicoureteric junction (VUJ). The implication of this hypothesis is that it alters the scientific basis of the understanding of the VUJ. Furthermore, the application of colour Doppler US to ureteric jets may provide a non-invasive technique to study the physiology or pathophysiology of the VUJ in humans. This might shed light on new novel approaches to the monitoring and treatment of diseases related to VUJ function. [ABSTRACT FROM AUTHOR]