CASE REPORT Not lost to follow-up: A rare case of CHILD syndrome in a boy reappears Nathan Fackler, MS,a,b Cameron Zachary, MS,a,b Dong Joo Kim, MD,a Janellen Smith, MD,a and Hege Grande Sarpa, MDa,c Irvine and Mission Viejo, California and Washington, DC Key words: CHILD syndrome; congenital hemidysplasia with ichthyosiform nevus and limb defects syndrome; congenital nevus; erythema; genodermatosis; hemidysplasia; limb defect; scaling; X-linked dominant. INTRODUCTION Abbreviations used: Congenital hemidysplasia with ichthyosiform nevus and limb defects (CHILD) syndrome is an CHILD: Congenital hemidysplasia with ichthyo- siform nevus and limb defects exceedingly rare, X-linked dominant genetic disor- CNS: central nervous system der of lipid metabolism that arises from mutations in NSDHL: NAD(P) dependent steroid NAD(P) dependent steroid dehydrogenase-like dehydrogenase-like gene SHH: sonic hedgehog hormone gene (NSDHL), which encodes 3b-hydroxysteroid- dehydrogenase, an enzyme essential to cholesterol synthesis. Cholesterol plays a crucial role in hedge- hog signaling during normal mammalian develop- CASE REPORT ment, thus explaining the striking right-to-left A 24-year-old man with CHILD syndrome (NSDHL 2,3 unilateralism of both cutaneous and visceral man- mutation c.262C[T, p.R88X) presented for follow- ifestations typified by this condition. Presenting at up of right-sided, mildly pruritic, erythematous birth or in the neonatal period, cutaneous findings ichthyosiform nevus sparing the face. The overall are unilateral erythema and scaling that progress to area and distribution of involvement remained increasingly hyperkeratotic, verrucous plaques or relatively stable over the years without much spread bands, sometimes Blaschkoid; partial spontaneous aside from slight expansion proportional to growth. regression may occur over time. Skeletal defects, He was treated in the past with topical corticoste- ranging from hypoplasia to complete amelia, and roids, emollients, retinoids, and azole antifungals organ hypoplasia are likewise ipsilateral. CHILD with minimal improvement. Dermabrasion of the syndrome is predominantly seen in females, as it is affected areas on the trunk was gratifying initially but generally lethal in affected male embryos. In fact, was ultimately nonsustained, with complete recur- there are currently only 2 reported cases in the rence to original thickness within 8 months. The literature of this disorder in males, one of whom we patient is currently undergoing treatment with a 2% saw for follow-up nearly 20 years after his original simvastatin, 2% cholesterol compounded ointment descriptionin1996.1 Hereweprovideanupdateon applied twice daily to existing lesions with signifi- his clinical status and disease progression, as well as cant, sustained improvement. advances in the current understanding of disease The patient was born with a hypoplastic right leg pathogenesis and management of this rare lacking a fibula. Correctional attempts were made to condition. salvage the lower leg, but he ultimately required From the Department of Dermatology, the University of California, JAAD Case Reports 2018;4:1010-3. Irvinea; Georgetown University, School of Medicineb; and the 2352-5126 Department of Dermatology, Southern California Kaiser Perma- Ó 2018 by the American Academy of Dermatology, Inc. Published nente Medical Group.c by Elsevier, Inc. All rights reserved. This is an open access article Funding sources: None. under the CC BY-NC-ND license (http://creativecommons.org/ Conflicts of interest: None disclosed. licenses/by-nc-nd/4.0/). Correspondence to: Dong Joo Kim, MD, University of California https://doi.org/10.1016/j.jdcr.2018.10.001 Irvine, Department of Dermatology, 118 Med Surg 1, Irvine, CA 92697-2400. E-mail: [email protected]. 1010 JAAD CASE REPORTS Fackler et al 1011 VOLUME 4, NUMBER 10 Fig 1. CHILD syndrome in a man. Right-sided congenital nevus with scaling and erythema involving the trunk (A) with Blaschkoid extension down the right anteromedial arm (B) and groin (C) extending down the ipsilateral thigh (D) in the setting of above-the-knee amputation for nonsalvageable lower limb defect. above-the-knee amputation with no further compli- and chest extending down the right anteromedial cations. Otherwise, no organ hypoplasia was found arm along Blaschko lines (Fig 1). The affected at the time of initial description in 1996, with normal- areas on the thigh and groin were erythematous sized heart, brain, eyes, and kidneys noted. Nearly and thickened with waxy, yellowish scale, espe- 20 years later, the patient remained in good health cially overlying the thigh. The affected areas on the overall without any chronic comorbid conditions or abdomen and trunk were relatively clear in com- medications. parison, with faintly red-brown pigmentation and On examination, there was a well-marginated without significant hyperkeratosis or thickening. nevus involving the right thigh, groin, abdomen Periumbilically, to the right of midline, was a 1012 Fackler et al JAAD CASE REPORTS NOVEMBER 2018 geometric atrophic scar-like plaque, and around sometimes seen in the CNS and limbs of patients the right superior axillary fold was a curvilinear with CHILD syndrome.10 hyperkeratotic band with erythematous and verru- Historical therapies for the cutaneous symptoms ciform accentuation centrally. of CHILD syndrome include topical ointments (corticosteroids, emollients, retinoids, and azole antifungals such as ketoconazole11), oral agents DISCUSSION (ketoconazole,11 retinoids, and methotrexate), and CHILD syndrome is an X-linked dominant disor- surgical approaches (dermabrasion and skin graft- der of lipid metabolism that is usually lethal in males. ing). These treatments have varying degrees of As such, the prevalence of this disorder in males is efficacy but do not address the underlying defect exceedingly rare, as is the case in other X-linked in cholesterol.4 Skin grafting had been rather suc- dominant disorders, such as incontinentia pigmenti. cessful because the unaffected donor graft does not For our patient, with normal 46, XY karyotype express the mutated allele and exhibits donor identified on peripheral blood mononuclear cell dominance.12 However, this invasive approach cytogenetic analysis, the proposed mechanism is an can be costly and is not feasible in patients with acquired, postzygotic mutation in NSDHL with sub- nevi that take up large portions of their body sequent mosaicism. Depending on the timing of his surface. Today, treatment with topical 2% statin mutation, this may account for the complete lack of (lovastatin or simvastatin) and 2% cholesterol com- ipsilateral hemidysplasia of his internal organs, poundedointmentwasfoundtobeeffectivein8 which tend to develop at earlier Carnegie stages patients treated over 6 case reports. Twice-daily relative to skeletal structures. Furthermore, the post- application for 6 months followed by 1 to 2 times zygotic mutation in our patient may have occurred weekly for maintenance produced marked between days 22 and 55 of development, allowing improvement, with clinical improvement seen as for initiation of central nervous system (CNS) and earlyas3weeksintotreatment.4-9 This new kidney embryogenesis but not fibula development. pathogenesis-directed therapy is a cost-effective Interestingly, of the 33 reported cases of CHILD and noninvasive approach to treating the cutaneous syndrome in the literature, only 5 had internal organ manifestations of CHILD syndrome. involvement beyond ipsilateral musculoskeletal hy- 2-9 poplasias. The most common organs involved REFERENCES were the kidneys (3) and CNS (2), although lung, 1. Happle R, Effendy I, Megahed M, Orlow SJ, Kuster€ W. CHILD vocal cord, and auditory nerve involvement were syndrome in a boy. Am J Med Genet. 1996;62(2):192-194. € also reported. 2. 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