Clinical details of individuals with Rauch-Steindl syndrome due to NSD2 truncating variants.

BACKGROUND: Rauch-Steindl syndrome (RAUST) is a very rare genetic syndrome caused by a pathogenic variant in NSD2 on chromosome 4p16.3. Although NSD2 was previously thought to be the major gene in Wolf-Hirschhorn syndrome (WHS), a contiguous gene syndrome of chromosome 4p16.3 deletion, RAUST has been found to present different facial and clinical features from WHS. In this study, we report the details of two newly diagnosed individuals with RAUST in order to better understand the molecular and clinical features of RAUST. METHODS: Whole-genome sequencing was performed on two individuals with psychomotor delay and growth failure. Detailed clinical evaluation of growth parameters, craniofacial features, electroencephalogram (EEG), magnetic resonance imaging of the brain, and developmental assessment were performed. RESULTS: Both individuals had de novo truncating variants in NSD2. One had a novel variant (c.2470C>T, p.Arg824*), and the other had a recurrent variant (c.4028del, p.Pro1343Glnfs*49). Both exhibited characteristic RAUST facial features, growth failure, and mild psychomotor delay. A novel finding of RAUST was seen in individual 2, a Chiari malformation type 1, and both showed delayed bone age. They lacked common WHS features such as congenital heart defects, cleft lip/palate, and seizures (EEG with abnormal findings). CONCLUSION: We present a novel variant and clinical presentations of RAUST, expand the molecular and clinical diversity of RAUST, and improve our understanding of this rare syndrome, which is distinct from WHS. Further researches are needed on more RAUST cases and on functional analysis of NSD2.

Uncommon Oral Cleft in Wolf-Hirschhorn Syndrome

Wolf-Hirschhorn syndrome (WHS) is a syndrome with craniofacial and systemic abnormalities, which is related to 4p deletion. A 3-month old girl with an undiagnosed syndrome was referred for evaluation of the cleft lip and palate. Hypotonia, short stature, cardiac malformation, hypertrophied clitoris, and atypical thumb of both hands was observed. Microcephaly, low-set ear, prominent glabella, downslanting palpebral fissures, a characteristic "Greek warrior helmet" appearance, micrognathia, ears with pits/tags and bilateral incomplete cleft lip apart from incomplete cleft palate were observed as craniofacial findings. With clinical diagnosis of WHS, blood was subjected to karyotyping, which showed a 4p15.2 deletion, consistent with the condition. Here is reported the case of this WHS patient with an uncommon oral cleft extending the phenotypic spectrum of the disorder. The child was referred to a multidisciplinary team to reparative surgery of the cleft lip and palate. The patient is on regular medical follow-up and will be further assisted by dentists, physical therapists, occupational therapists and psychologists. The genotype-phenotype correlation of the affected patient with previous WSH syndrome reports is described.

A síndrome de Wolf-Hirschhorn (WHS) é uma condição genética caracterizada por anomalias craniofaciais e sistêmicas, causada por deleção cromossômica na região 4p. Paciente de 3 meses de idade, gênero feminino, foi encaminhada para avaliação de fissura de lábio e fissura palatina, associada a uma síndrome não diagnosticada. A paciente apresentava-se com hipotonia, baixa estatura, malformação cardíaca, clitóris hipertrofiado e implantação atípica do polegar nas duas mãos. Microcefalia, baixa implantação da orelha, glabela proeminente, inclinação baixa das fissuras palpebrais, aparência característica de capacete de guerreiro grego, micrognatia, fossetas em orelhas, fissura labial bilateral incompleta e fissura palatina incompleta foram observadas como características craniofaciais. Com um diagnóstico clínico de WHS, foi realizado o cariótipo, que mostrou a deleção 4p15.2, consistente com a condição. Esse relato de caso apresenta um caso de WHS, com uma fissura oral incomum, ampliando o espectro fenotípico da doença. A paciente foi encaminhada a tratamento com equipe multidisciplinar para correção cirúrgica da fissura labial e palatina. Encontra-se em acompanhamento médico bem como odontológico, fisioterapêutico e em terapia ocupacional e psicológica. Uma correlação entre genótipo e fenótipo pode ser observada nesse relato da síndrome de WHS.

Síndrome de Wolf-Hirschhorn: reporte de un caso clínico y revisión de la literatura / Wolf-Hirschhorn syndrome: case report and literature review

El síndrome de Wolf-Hirschhorn es un trastorno cromosómico atribuible a una delección parcial del brazo corto del cromosoma 4 (4p-). Está caracterizado por hallazgos craneofaciales típicos en la infancia (“apariencia de guerrero griego” de la nariz, microcefalia, frente alta con glabela prominente, hipertelorismo, cejas muy arqueadas, filtrum corto, boca en carpa, y micrognatia, entre otros), retardo del crecimiento pre y postnatal, hipotonía y retardo del desarrollo. Los pacientes también pueden tener epilepsia y anormalidades que involucran otros órganos. El diagnóstico puede ser realizado por análisis citogenético convencional, el cual detecta la mayoría de los casos. El tratamiento incluye rehabilitación, terapia de lenguaje, drogas antiepilépticas cuando son necesarias, alimentación por gavaje o gastrostomía para las dificultades de la alimentación y terapia de soporte. Femenina de 10 meses de edad, quien presenta anomalías craneofaciales características, pie equinovaro bilateral, hipotonía, reflujo gastroesofágico, epilepsia, retardo del crecimiento y del desarrollo. El diagnóstico fue confirmado por detección de una delección de 4p que involucraba a la región crítica para este síndrome. Esta paciente recibe actualmente rehabilitación, medicación antirreflujo y ácido valproico. Esta condición debe ser reconocida por los pediatras, a fin de poder ofrecer un adecuado manejo a estos pacientes y sus familias.

Wolf-Hirschhorn Syndrome is a cromosomal disorder attributable to partial deletion of the short arm of chromosome 4(4p-). It is characterized by typical craneofacial features in infancy (“Greek warrior appearance” of the nose, microcephaly, high forehead with prominent glabella, hypertelorism, highly arched eyebrows, short philtrum, downturned mouth and micrognathia, among others), pre and postnatal growth retardation, hypotonia and developmental delay. Patients can also have epilepsy and abnormalities that involve other organs. Diagnosis can be made by conventional cytogenetic analysis which detects most of the cases. Treatment includes rehabilitation, speech therapy, antiepileptic drugs when necessary, gavage feeding or gastrostomy for feeding difficulties and standard management of other anomalies. 10 month-old female who presents characteristic craniofacial anomalies, clubfeet, hypotonia, gastroesofageal reflux, epilepsy, growth retardation and developmental delay. Diagnosis was confirmed by detection of a deletion of 4p that involved the critical region of the syndrome. This patient receives rehabilitation, antireflux medication and valproic acid. This condition must be recognized by pediatricians in order to offer adecuated management to these patients and their families.