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Background: Lacrimo-auriculo-dento-digital (LADD) syndrome is a rare autosomal dominant disorder caused by mutations in one of the three genes: fibroblast growth factor receptor 2 (FGFR2), FGFR3, or FGF10. Affected patients have hypoplasia/aplasia of lacrimal ducts/glands, hypoplasia/aplasia of salivary glands, dental anomalies, ear anomalies, hearing loss, and digital anomalies., Case Presentation: Proband was an 11-year-old male with xerostomia, xerophthalmia, and a referring diagnosis of Sjogren syndrome. He presented with microdontia, hypodontia, low-set/cupped ear auricles, and hearing loss in the left ear., Methods: Whole exome sequencing (WES) was performed on proband. Variations and segregation within the family were verified using Sanger sequencing., Results: Molecular studies revealed a novel heterozygous missense mutation in exon 11 of FGFR2: c.1547C>T (p.Ala516Val), compatible with LADD syndrome., Conclusion: To the best of our knowledge, this is the first report of a family with LADD syndrome in Korea. The combination of xerostomia and xerophthalmia, seen in patients with LADD syndrome, may be misdiagnosed as Sjogren syndrome. WES may be a useful clinical tool in ascertaining the affected gene in patients with suspected genetic disorders. Here, a literature review and summary of 23 case reports/series of LADD syndrome are presented, which may help to identify patients with this condition., (© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

The skeletal structure of the mammalian middle ear, which is composed of three endochondral ossicles suspended within a membranous air-filled capsule, plays a critical role in conducting sound. Gene mutations that alter skeletal development in the middle ear result in auditory impairment. Mutations in fibroblast growth factor receptor 2 (FGFR2), an important regulator of endochondral and intramembranous bone formation, cause a spectrum of congenital skeletal disorders featuring conductive hearing loss. Although the middle ear malformations in multiple FGFR2 gain-of-function disorders are clinically characterized, those in the FGFR2 loss-of-function disorder lacrimo-auriculo-dento-digital (LADD) syndrome are relatively undescribed. To better understand conductive hearing loss in LADD, we examined the middle ear skeleton of mice with conditional loss of Fgfr2. We find that decreased auditory function in Fgfr2 mutant mice correlates with hypoplasia of the auditory bulla and ectopic bone growth at sites of tendon/ligament attachment. We show that ectopic bone associated with the intra-articular ligaments of the incudomalleal joint is derived from Scx-expressing cells and preceded by decreased expression of the joint progenitor marker Gdf5. Together, these results identify a role for Fgfr2 in development of the middle ear skeletal tissues and suggest potential causes for conductive hearing loss in LADD syndrome., (© 2018 Wiley Periodicals, Inc.)

Lacrimo-auriculo-dento-digital syndrome (LADD) is a multiple congenital anomaly and a genetically heterogeneous disorder. The aim of this study was to identify the pathogenic gene in an Iranian family with LADD syndrome and review the literature on reported mutations that involved in pathogenesis of LADD syndrome. One novel variant, c.1882 G > A, in fibroblast growth factor receptor 3 (FGFR3) was identified by next generation sequencing and Sanger sequencing. The heterozygous FGFR3 c.1882 G > A variant results in substitution of aspartic acid with asparagine at amino acid 628 (p.D628N) and co-segregated with the phenotype in the LADD family. Our findings suggest that the heterozygous FGFR3 c.1882 G > A variant might be the pathogenic mutation, because this amino acid is conserved in several species. Our data extend the mutation spectrum of the FGFR3 gene and have important implications for genetic counseling for the families. This is the second report of FGFR3 involvement in syndromic deafness in humans, and confirms the gene's positive role in inner ear development. In addition, this is the first FGFR3 mutation recognized in the Iranian LADD family., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose: Lacrimo-auriculo-dento-digital (LADD) syndrome is an autosomal dominant disorder displaying variable expression of multiple congenital anomalies including hypoplasia or aplasia of the lacrimal and salivary systems causing abnormal tearing and dry mouth. Mutations in the FGF10 , FGFR2 , and FGFR3 genes were found to cause some cases of LADD syndrome in prior genetic studies. The goal of this study is to identify the genetic basis of a case of LADD syndrome with glaucoma and thin central corneal thickness (CCT)., Methods: Whole exome sequencing was performed, and previously described disease-causing genes ( FGF10, FGFR2, and FGFR3 ) were first evaluated for mutations. Fifty-eight additional prioritized candidate genes were identified by searching gene annotations for features of LADD syndrome. The potential pathogenicity of the identified mutations was assessed by determining their frequency in large public exome databases; through sequence analysis using the Blosum62 matrix, PolyPhen2, and SIFT algorithms; and through homology analyses. A structural analysis of the effects of the top candidate mutation in tumor protein 63 (TP63) was also conducted by superimposing the mutation over the solved crystal structure., Results: No mutations were detected in FGF10 , FGFR2 , or FGFR3 . The LADD syndrome patient's exome data was searched for mutations in the 58 candidate genes and only one mutation was detected, an Arg343Trp mutation in the tumor protein 63 ( TP63 ) gene. This TP63 mutation is absent from the gnomAD sequence database. Analysis of the Arg343Trp mutation with Blosum62, PolyPhen2, and SIFT all suggest it is pathogenic. This arginine residue is highly conserved in orthologous genes. Finally, crystal structure analysis showed that the Arg343Trp mutation causes a significant alteration in the structure of TP63's DNA binding domain., Conclusions: We report a patient with no mutations in known LADD syndrome genes ( FGF10 , FGFR2 , and FGFR3 ). Our analysis provides strong evidence that the Arg343Trp mutation in TP63 caused LADD syndrome in our patient and that TP63 is a fourth gene contributing to this condition. TP63 encodes a transcription factor involved in the development and differentiation of tissues affected by LADD syndrome. These data suggest that TP63 is a novel LADD syndrome gene and may also influence corneal thickness and risk for open-angle glaucoma.

Background and Overview: Lacrimo-auriculo-dento-digital (LADD) syndrome is an autosomal dominant disorder with variable lacrimal and salivary gland hypoplasia and aplasia, auricular anomalies and hearing loss, dental defects and caries, and digital anomalies., Case Description: The authors present the cases of 2 unrelated children with enamel defects and history of dry mouth leading to recurrent dental caries. The referring diagnoses were Sjögren disease and hypohidrotic ectodermal dysplasia, respectively. The geneticist suspected LADD syndrome, which was confirmed by means of molecular studies showing mutations of 2 genes: fibroblast growth factor receptor 2 and fibroblast growth factor 10, respectively. Similarly affected relatives indicated an autosomal dominant inheritance. These relatives needed multiple dental rehabilitations during childhood and dentures in adulthood., Conclusions and Practical Implications: Dry mouth, multiple caries, enamel defects, and abnormal tooth morphology were the reasons for seeking care from dentists. However, clinical evaluation and diagnostic imaging studies helped identify anomalies of the lacrimal and salivary glands, ears, and digits, indicating involvement of different areas of the body, compatible with LADD syndrome. Accordingly, dentists should consider genetic disorders in patients with multiple anomalies. For instance, oculodentodigital syndrome, oral-facial-digital syndrome, and LADD syndrome (among others) may have dental issues as the major clinical manifestation. Accurate identification of a particular syndrome is now commonplace with the use of genetic testing. When a patient has multiple anomalies suggestive of a syndromic condition, appropriate genetic testing can help verify the clinical diagnosis. Keeping genetics in mind helps earlier identification of other affected family members with diagnostic genetic testing and appropriate treatment; the economic advantage is to shorten the diagnostic odyssey and possibly preserve dentition., (Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Heterozygous mutations in the gene encoding fibroblast growth factor 10 (FGF10) or its cognate receptor, FGF-receptor 2 IIIb result in two human syndromes - LADD (lacrimo-auriculo-dento-digital) and ALSG (aplasia of lacrimal and salivary glands). To date, the partial loss-of-FGF10 function in these patients has been attributed solely to perturbed paracrine signalling functions between FGF10-producing mesenchymal cells and FGF10-responsive epithelial cells. However, the functioning of a LADD-causing G138E FGF10 mutation, which falls outside its receptor interaction interface, has remained enigmatic. In the present study, we interrogated this mutation in the context of FGF10's protein sequence and three-dimensional structure, and followed the subcellular fate of tagged proteins containing this or other combinatorial FGF10 mutations, in vitro We report that FGF10 harbours two putative nuclear localization sequences (NLSs), termed NLS1 and NLS2, which individually or co-operatively promote nuclear translocation of FGF10. Furthermore, FGF10 localizes to a subset of dense fibrillar components of the nucleolus. G138E falls within NLS1 and abrogates FGF10's nuclear translocation whilst attenuating its progression along the secretory pathway. Our findings suggest that in addition to its paracrine roles, FGF10 may normally play intracrine role/s within FGF10-producing cells. Thus, G138E may disrupt both paracrine and intracrine function/s of FGF10 through attenuated secretion and nuclear translocation, respectively., (© 2016 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.)

Lacrimo-auriculo-dento-digital syndrome (LADD syndrome), also known as Levy-Hollister syndrome, is an autosomal dominant defect with variability on phenotypical expression. This syndrome is characterised by the association of dysplasia in various organs and systems that affect craniofacial structures, including lachrymal and salivary glands, teeth, internal and external ear, and the bone skeleton. We present this unusual and almost unknown syndrome (the first case in our state, with only about 100 cases described in the world, distributed in a few families) in a teenager of 17 years admitted to PICU for another reason. After the physical examination, a clinical diagnosis was made in the entire family branch., (Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.)

Background/purpose: Despite the similar clinical phenotype of the Saethre-Chotzen and Muenke craniosynostoses, the 2 syndromes are now genotypically distinct. Patients with Saethre-Chotzen and Muenke syndromes carry mutations in the TWIST and fibroblast growth factor receptor (FGFR) 3 genes, respectively. We sought to assess possible ocular phenotypic differences in patients with mutations of either gene previously grouped according to phenotype only., Methods: A retrospective chart review was performed for 21 children with known mutations of the TWIST (n=10) or the FGFR3 (n=11) genes. Data gathered included patient sex, age, family craniofacial history, craniofacial and ophthalmic surgeries, type of strabismus, ptosis, cycloplegic refraction, visual acuity, the presence of amblyopia, nasolacrimal duct obstruction (NLDO), nystagmus, hypertelorism, epicanthal fold anomalies, and any ocular structural abnormalities., Results: In the TWIST group, ptosis was present in 90%, amblyopia in 70%, horizontal strabismus in 70%, vertical strabismus in 60%, NLDO in 60%, astigmatism in 50%, inferior oblique overaction (IOOA) in 40%, hyperopia in 40%, myopia in 30%, nystagmus in 30%, and optic nerve findings in 30%. In the FGFR3 group, ptosis was present in 36%, amblyopia in 18%, horizontal strabismus in 55%, vertical strabismus in 36%, NLDO in 0%, astigmatism in 9%, IOOA in 45%, hyperopia in 27%, myopia in 18%, nystagmus in 18%, and optic nerve findings in 27%., Conclusions: Patients with TWIST gene mutations may have more ophthalmic abnormalities, including more strabismus, ptosis, NLDO, astigmatism, vertical deviations, and amblyopia compared with patients with FGFR3 gene mutations.

The triple A or Allgrove's syndrome is an autosomal recessive disorder characterized by the triad of achalasia cardia, alacrima and ACTH resistant adrenocortical insufficiency. Mutations of the Achalasia-Addisonianism-Alacrima-Syndrome (AAAS) gene on chromosome 12q13 are associated with this syndrome. We report an Indian family where two siblings were homozygous for a known mutation of the AAAS gene and presented with the classical triad of symptoms. The mother and the brother were heterozygous and asymptomatic. The affected siblings had iron deficiency anemia and the younger sister had pes cavus and palmoplantar keratosis. Neurological symptoms were absent in both affected children. Recognition of this syndrome can lead to early treatment of adrenal insufficency and genetic counselling.