Johanson-Blizzard syndrome (JBS) is a rare hereditary autosomal recessive disorder caused by a mutation in the ubiquitin protein ligase E3 component n-recognin 1 (UBR1) gene. This syndrome is characterized by the following typical clinical features: hypoplasia or aplasia of the alae nasi, congenital scalp defects, sensorineural hearing loss, hypothyroidism, growth retardation, psychomotor retardation, imperforate anus, genitourinary anomalies, and atypical hair patterns. Here, we describe a case of a 12-year-old girl with JBS of consanguineous parents. During the last trimester of pregnancy, a congenital abnormality affecting the nose was detected. Immediately after birth, the clinical examination revealed dysmorphic features in the form of hypoplastic alae nasi, microcephaly, mild hypotelorism, and cutis aplasia on the scalp. The genetic testing of the patient showed a novel sequence change mutation of the UBR1 gene (1bp duplication causing a frameshift), while both parents were carriers for this mutation. Moreover, a diagnosis of pancreatic insufficiency and subclinical hypothyroidism was made based on clinical presentation and laboratory results. The patient was started on pancreatic enzyme replacement therapy and fat-soluble vitamins, minerals, and antioxidant syrup. Further assessment revealed hypotonia, growth impairment, delay in reaching developmental milestones, and bilateral profound sensorineural hearing loss, which was managed with bilateral cochlear implantation. In addition, the patient underwent multiple craniofacial reconstructive surgeries. This case report highlights the importance of early diagnosis and multidisciplinary care of patients with JBS.

Congenital exocrine pancreatic insufficiency is a rare condition. In a vast majority of patients, exocrine dysfunction occurs as part of a multisystemic disease, the most prevalent being cystic fibrosis and Shwachman-Bodian-Diamond syndrome. Recent fundamental studies have increased our understanding of the pathophysiology of these diseases. Exocrine pancreatic dysfunction should be considered in children with failure to thrive and fatty stools. Treatment is mainly supportive and consists of pancreatic enzyme replacement and liposoluble vitamins supplementation.

Johanson-Blizzard syndrome (JBS) is a rare autosomal recessive hereditary disorder characterized by multi-system involvement and facial dysmorphic features. One of the most common symptoms in JBS patients is bilateral severe to profound sensorineural hearing loss. The objective of this report is to highlight the performance of those patients after receiving cochlear implants (CI) as a management for their hearing loss. In this study, we reviewed the medical records of one female child diagnosed with JBS before and after cochlear implantation, with a particular focus on their auditory and language performance. After receiving the cochlear implant, our patient showed substantial improvement in her hearing threshold and communication abilities when compared to the preoperative condition. In conclusion, although cochlear implantation is considered a good approach for the management of JBS patients, the development of spoken language is not always achieved.

Johanson-Blizzard syndrome (JBS, MIM #243800) is a very rare autosomal recessive disorder characterized by exocrine pancreatic insufficiency, nasal wing hypoplasia, hypodontia, and other abnormalities. JBS is caused by mutations of the UBR1 gene (MIM *605981), encoding a ubiquitin ligase of the N-end rule pathway.
Molecular findings in a total of 65 unrelated patients with a clinical diagnosis of JBS who were previously screened for UBR1 mutations by Sanger sequencing were reviewed and cases lacking a disease-causing UBR1 mutation on either one or both alleles were included in this study. In order to discover mutations that are not detectable by Sanger sequencing, we designed a probe set for multiplex ligation-dependent probe amplification (MLPA) analysis of the UBR1 gene and analyzed the copy number status of all 47 UBR1 exons.
Our previous studies using Sanger sequencing could detect mutations in 93.1% of 130 disease-associated UBR1 alleles. Six patients with a highly suggestive clinical diagnosis of JBS and unsolved genotype were included in this study. MLPA analysis detected six alleles harboring exon deletions/duplications, thereby raising the mutation detection rate in the entire cohort to 97.7% (127/130 alleles).
We conclude that single or multi-exon deletions or duplications account for a substantial proportion of JBS-associated UBR1 mutations.

OBJECTIVE: The UBR1 gene encodes the enzyme ubiquitin-protein ligase E3 component n-recognin 1. Loss-of-function mutations in the UBR1 gene cause Johanson-Blizzard syndrome, which involves pancreatic exocrine insufficiency. No previous studies have examined an association of UBR1 variants with pancreatitis, in part due to the large size of the gene. This study aimed to clarify whether UBR1 variants are associated with chronic pancreatitis (CP) by the application of targeted next generation sequencing.
METHODS: Exon sequences of the UBR1 gene from 389 Japanese patients with CP (188 idiopathic, 172 alcoholic, 20 hereditary, 9 familial) were captured by the HaloPlex target enrichment technology and subjected to next generation sequencing.
RESULTS: Ninety nine point two % of the coding regions of the UBR1 gene could be sequenced by ≥ 20 reads with a mean read depth of 595 and a median depth of 399. Fifteen non-synonymous variants including three novel ones [c.4514T > C (p.I1505T), c.4828C > G (p.H1610D) and c.4856A > T (p.D1619V)] and two synonymous variants were identified in the exonic regions. The frequency of any non-synonymous or synonymous variants was not different between the patients with CP and controls.
CONCLUSIONS: Variants in the UBR1 gene were not associated with CP in Japan.

Johanson-Blizzard syndrome (JBS) is a rare, autosomal recessive disorder characterized by exocrine pancreatic insufficiency, typical facial features, dental anomalies, hypothyroidism, sensorineural hearing loss, scalp defects, urogenital and anorectal anomalies, short stature, and cognitive impairment of variable degree. This syndrome is caused by a defect of the E3 ubiquitin ligase UBR1, which is part of the proteolytic N-end rule pathway. Herein, we review previously reported (n = 29) and a total of 31 novel UBR1 mutations in relation to the associated phenotype in patients from 50 unrelated families. Mutation types include nonsense, frameshift, splice site, missense, and small in-frame deletions consistent with the hypothesis that loss of UBR1 protein function is the molecular basis of JBS. There is an association of missense mutations and small in-frame deletions with milder physical abnormalities and a normal intellectual capacity, thus suggesting that at least some of these may represent hypomorphic UBR1 alleles. The review of clinical data of a large number of molecularly confirmed JBS cases allows us to define minimal clinical criteria for the diagnosis of JBS. For all previously reported and novel UBR1 mutations together with their clinical data, a mutation database has been established at LOVD.

Johanson-Blizzard syndrome is rare and involves multiple congenital anomalies, including bilateral absence or deficiency of the nasal alae, giving the affected infant a characteristic appearance. Two cases are described that illustrate the difficulties of nasal reconstruction in young children. Surgical options and the timing of intervention are discussed.
Le syndrome de Johanson-Blizzard est rare. Il comporte des anomalies congénitales multiples, y compris une absence bilatérale ou une anomalie des ailes du nez, qui donne à l’enfant atteint une apparence caractéristique. Deux cas sont décrits qui illustrent les difficultés de la reconstruction nasale chez les jeunes enfants. Sont examinés les possibilités chirurgicales et le moment de prévoir l’intervention.

Johanson-Blizzard syndrome (JBS) is a rare autosomal recessive disease characterized by exocrine pancreatic insufficiency, hypoplastic or aplastic nasal alae, cutis aplasia on the scalp, and other features including developmental delay, failure to thrive, hearing loss, mental retardation, hypothyroidism, dental abnormalities, and anomalies in cardiac and genitourinary systems. More than 60 cases of this syndrome have been reported to date. We describe the case of a male infant with typical symptoms of JBS. In addition, a new clinical feature which has not previously been documented, that is anemia requiring frequent blood transfusions and mild to moderate thrombocytopenia was observed. A molecular study was performed which revealed a novel homozygous UBR1 mutation. Possible explanations for this new association are discussed.