X-linked hypophosphatemic rickets is an X-linked dominantly inherited disorder characterized by defects in renal phosphate transport leading to phosphate wasting and hypophosphatemia. In this report, we describe a case of X-linked hypophosphatemic rickets in a patient with a rare pathogenic PHEX variant. The 25-year-old female patient came to our clinic for genetic counseling regarding presumed genetic disease and pregnancy. When she was 9 years old, she had been diagnosed with vitamin D-resistant rickets based on laboratory results and symptoms. She had undergone orthopedic surgery due to bowing leg deformities. Since then, she was intermittently self-prescribing oral phosphate and calcium supplements. At 25 years old, she was diagnosed with X-linked hypophosphatemic rickets with a rare pathogenic PHEX variant (c.1483-1G>C) by next-generation sequencing. This is the second report of the c.1483-1G>C variant to date, and her pathogenicity was confirmed based on the most recent guideline. Traditionally, the disease had been diagnosed mostly based on clinical findings. However, with advancements in genetic testing, genetic confirmation has become an imperative part of diagnostic workup. Herein, we report a 25-year-old female Korean patient diagnosed with X-linked hypophosphatemic rickets harboring a rare pathogenic PHEX variant.

X-linked hypophosphatemic rickets is an X-linked dominantly inherited disorder characterized by defects in renal phosphate transport leading to phosphate wasting and hypophosphatemia. In this report, we describe a case of X-linked hypophosphatemic rickets in a patient with a rare pathogenic PHEX variant. The 25-year-old female patient came to our clinic for genetic counseling regarding presumed genetic disease and pregnancy. When she was 9 years old, she had been diagnosed with vitamin D-resistant rickets based on laboratory results and symptoms. She had undergone orthopedic surgery due to bowing leg deformities. Since then, she was intermittently self-prescribing oral phosphate and calcium supplements. At 25 years old, she was diagnosed with X-linked hypophosphatemic rickets with a rare pathogenic PHEX variant (c.1483-1G>C) by next-generation sequencing. This is the second report of the c.1483-1G>C variant to date, and her pathogenicity was confirmed based on the most recent guideline. Traditionally, the disease had been diagnosed mostly based on clinical findings. However, with advancements in genetic testing, genetic confirmation has become an imperative part of diagnostic workup. Herein, we report a 25-year-old female Korean patient diagnosed with X-linked hypophosphatemic rickets harboring a rare pathogenic PHEX variant.

Objective: This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait. Methods: The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months. Results: The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age. Conclusion The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.

Objective: This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait. Methods: The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months. Results: The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age. Conclusion The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.

Objective: This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait. Methods: The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months. Results: The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age. Conclusion The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.

Objective: This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait. Methods: The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months. Results: The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age. Conclusion The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.

Objective: This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait. Methods: The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months. Results: The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age. Conclusion The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.

Dystrophic epidermolysis bullosa (DEB) pruriginosa is a rare subtype of DEB characterized by multiple, violaceous, and severe pruritic lichenified nodules along with blisters. Here, we report the case of a Korean male who, since the age of 3 years, had multiple pruritic nodules with blisters on both lower extremities. Genetic testing is required to diagnose DEB pruriginosa because its clinical and histologic features are inconclusive. We identified compound heterozygous COL7A1 variants of c.5797C>T (p.R1933*) and c.3301C>T (p.R1101W) in the patient, leading to a diagnosis of recessive DEB pruriginosa. Among the variants identified, c.3301C>T is a novel missense variant that has not been reported previously. This variant is in exon 26, which encodes von Willebrand factor A (vWFA) in collagen type VII. vWFA is known to preserve normal dermal structures by interacting with dermal collagens and basement membranes. Considering that this variant contradicts the general concept that autosomal dominant inheritance is more common and that variants typically occur in the triple helical collagenous domain of COL7A1 in DEB pruriginosa, we focus on the rarity of this case and the possible pathogenic role of the c.3301C>T (p.R1101W) variant.

We performed a point seroprevalence survey of measles among healthcare workers (HCWs) at two Korean teaching hospitals in 2019. A total of 2,830 HCWs underwent an antibody test.The overall seropositivity of measles was 93.1%. The seroprevalence of measles was lowest in HCWs aged 20 - 24 years (81.2%), followed by those aged 25 - 29 years (90.1%). The rates of anti-measles IgG positivity were significantly different between the two hospitals (97.0% vs.89.4%, P <0.001). These results suggest that the seropositivity of measles in HCWs may differ depending on the hospital's vaccination policy.

Background and Objectives: Human mesenchymal stem cells (MSCs) are emerging as a treatment for atopic dermatitis (AD), a chronic inflammatory skin disorder that affects a large number of people across the world. Treatment of AD using human umbilical cord blood-derived MSCs (hUCB-MSCs) has recently been studied. However, the mechanism underlying their effect needs to be studied continuously. Thus, the objective of this study was to investigate the immunomodulatory effect of epidermal growth factor (EGF) secreted by hUCB-MSCs on AD. Methods: and Results: To explore the mechanism involved in the therapeutic effect of MSCs for AD, a secretome array was performed using culture medium of hUCB-MSCs. Among the list of genes common for epithelium development and skin diseases, we focused on the function of EGF. To elucidate the effect of EGF secreted by hUCB-MSCs, EGF was downregulated in hUCB-MSCs using EGF-targeting small interfering RNA. These cells were then co-cultured with keratinocytes, Th2 cells, and mast cells. Depletion of EGF disrupted immunomodulatory effects of hUCB-MSCs on these AD-related inflammatory cells. In a Dermatophagoides farinae-induced AD mouse model, subcutaneous injection of hUCB-MSCs ameliorated gross scoring, histopathologic damage, and mast cell infiltration. It also significantly reduced levels of inflammatory cytokines including interleukin (IL)-4, tumor necrosis factor (TNF)-α, thymus and activation-regulated chemokine (TARC), and IL-22, as well as IgE levels. These therapeutic effects were significantly attenuated at all evaluation points in mice injected with EGF-depleted hUCB-MSCs. Conclusions EGF secreted by hUCB-MSCs can improve AD by regulating inflammatory responses of keratinocytes, Th2 cells, and mast cells.