low-set ears

Neurodevelopmental Disorder with Progressive Microcephaly, Spasticity, and Brain Anomalies

Clinical Characteristics
Ocular Features: 

 Examined patients have optic atrophy with nystagmus and roving eye movements.

Systemic Features: 

There are extensive and, in most cases, progressive CNS abnormalities resulting in severe neurodevelopmental deficits.  Infants at birth have progressive truncal hypotonia and limb spasticity.  Motor deficits result in little spontaneous movement, resulting in poor sucking, and respiratory difficulties.  Language does not develop and there is profound mental retardation. Progressive microcephaly is a characteristic finding.  There are often extrapyramidal signs such as rigidity and dystonic posturing.

Dysmorphic features include a short nose, high-arched palate, low-set and posteriorly rotated ears, micrognathia, postaxial polydactyly, hirsutism, pectus carinatum, contractures of large joints, and hyperextensibility of small joints.

Brain imaging shows a progressive leukoencephalopathy, cerebral and cerebellar atrophy, and delayed myelination.  The corpus callosum is often thin and the ventricles appear enlarged.  The lifespan is generally short with death occurring in infancy or early childhood.

Genetics

This autosomal recessive disorder results from homozygous mutations in the PLAA gene (9p21). 

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

PLAA Mutations Cause a Lethal Infantile Epileptic Encephalopathy by Disrupting Ubiquitin-Mediated Endolysosomal Degradation of Synaptic Proteins

Hall EA, Nahorski MS, Murray LM, Shaheen R, Perkins E, Dissanayake KN, Kristaryanto Y, Jones RA, Vogt J, Rivagorda M, Handley MT, Mali GR, Quidwai T, Soares DC, Keighren MA, McKie L, Mort RL, Gammoh N, Garcia-Munoz A, Davey T, Vermeren M, Walsh D, Budd P, Aligianis IA, Faqeih E, Quigley AJ, Jackson IJ, Kulathu Y, Jackson M, Ribchester RR, von Kriegsheim A, Alkuraya FS, Woods CG, Maher ER, Mill P. PLAA Mutations Cause a Lethal Infantile Epileptic Encephalopathy by Disrupting Ubiquitin-Mediated Endolysosomal Degradation of Synaptic Proteins. Am J Hum Genet. 2017 May 4;100(5):706-724.

PubMed ID: 
28413018

Phospholipase A2-activating protein is associated with a novel form of leukoencephalopathy

Falik Zaccai TC, Savitzki D, Zivony-Elboum Y, Vilboux T, Fitts EC, Shoval Y, Kalfon L, Samra N, Keren Z, Gross B, Chasnyk N, Straussberg R, Mullikin JC, Teer JK, Geiger D, Kornitzer D, Bitterman-Deutsch O, Samson AO, Wakamiya M, Peterson JW, Kirtley ML, Pinchuk IV, Baze WB, Gahl WA, Kleta R, Anikster Y, Chopra AK. Phospholipase A2-activating protein is associated with a novel form of leukoencephalopathy. Brain. 2017 Feb;140(Pt 2):370-386.

PubMed ID: 
28007986

Ayme-Gripp Syndrome

Clinical Characteristics
Ocular Features: 

Most patients have congenital cataracts which may be mild and "oil drop" in appearance.  The eyes appear far apart, the eyebrows are broad, and the palpebral fissures may slant upward or downward.  Ptosis has been reported.  Aphakic glaucoma has been reported in one juvenile who had unilateral cataract surgery at 5 months of age.

Systemic Features: 

The phenotype is heterogeneous and not all patients have all features.  The facial features are said to resemble those of the Down syndrome with brachycephaly, a high forehead, and a flat midface with shallow orbits and malar hypoplasia.  The ears are small, low-set, and posteriorly rotated.  The nose is short and the nasal bridge is broad and flat.  The mouth is small and the upper lip is thin.  The scalp hair may be sparse and the nails sometimes appear dystrophic.

The fingers are sometimes brachydactylous and tapered.  Short stature is common and the joints may have limited motion.  Dislocation of the radial heads is seen rarely while radioulnar synostosis has been seen in a few individuals.  Postnatal short stature is common.

Seizures often occur.  The ventricles appear large and cerebral atrophy has been reported.  Intellectual disability and mental retardation are common. However, at least one individual attended university although he had been diagnosed in childhood with Asberger disease.   Neurosensory hearing loss is common.

Genetics

This autosomal dominant condition results from heterozygous mutations in the MAF (16q32.2) gene.  At least one mother/son transmission event has been reported.

Many of the same features are seen in what has been called the Fine-Lubinsky syndrome (601353) but without mutations in the MAF gene.  It may not be a unique disorder.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No general treatment has been reported but specific anomalies such as cataracts should be addressed.

References
Article Title: 

Mutations Impairing GSK3-Mediated MAF Phosphorylation Cause Cataract, Deafness, Intellectual Disability, Seizures, and a Down Syndrome-like Facies

Niceta M, Stellacci E, Gripp KW, Zampino G, Kousi M, Anselmi M, Traversa A, Ciolfi A, Stabley D, Bruselles A, Caputo V, Cecchetti S, Prudente S, Fiorenza MT, Boitani C, Philip N, Niyazov D, Leoni C, Nakane T, Keppler-Noreuil K, Braddock SR, Gillessen-Kaesbach G, Palleschi A, Campeau PM, Lee BH, Pouponnot C, Stella L, Bocchinfuso G, Katsanis N, Sol-Church K, Tartaglia M. Mutations Impairing GSK3-Mediated MAF Phosphorylation Cause Cataract, Deafness, Intellectual Disability, Seizures, and a Down Syndrome-like Facies. Am J Hum Genet. 2015 May 7;96(5):816-25.

PubMed ID: 
25865493

Retinitis Pigmentosa With or Without Skeletal Anomalies

Clinical Characteristics
Ocular Features: 

Downward slanting lid fissures may be detectable at birth as part of the general craniofacial dysmorphism.  Some degree of night blindness causes symptoms by the second decade of life and constricted visual fields with pigmented retinopathy and vessel narrowing can be detected.  The ERG shows reduced or absent responses.  The retinal phenotype is progressive.   

Systemic Features: 

Most but not all patients have skeletal anomalies.  Nonspecific craniofacial dysmorphology features are frequently present including frontal bossing, macrocephaly, low-set ears, large columella, hypoplastic nares, and malar hypoplasia.  A short neck, brachydactyly, and overall shortness of stature are often present.  Some individuals have nail dysplasia.  The proximal femoral metaphyses sometimes show chondrodysplasia.

There is often some degree of intellectual disability and there may be delays in speech, feeding, and walking.

Genetics

This disorder results from homozygous or compound heterozygous mutations in the CWC27 gene (5q12.3).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No general treatment has been reported.  Low vision aids and night vision devices may be helpful, especially for educational activities.

References
Article Title: 

Mutations in the Spliceosome Component CWC27 Cause Retinal Degeneration with or without Additional Developmental Anomalies

Xu M, Xie YA, Abouzeid H, Gordon CT, Fiorentino A, Sun Z, Lehman A, Osman IS, Dharmat R, Riveiro-Alvarez R, Bapst-Wicht L, Babino D, Arno G, Busetto V, Zhao L, Li H, Lopez-Martinez MA, Azevedo LF, Hubert L, Pontikos N, Eblimit A, Lorda-Sanchez I, Kheir V, Plagnol V, Oufadem M, Soens ZT, Yang L, Bole-Feysot C, Pfundt R, Allaman-Pillet N, Nitschke P, Cheetham ME, Lyonnet S, Agrawal SA, Li H, Pinton G, Michaelides M, Besmond C, Li Y, Yuan Z, von Lintig J, Webster AR, Le Hir H, Stoilov P; UK Inherited Retinal Dystrophy Consortium., Amiel J, Hardcastle AJ, Ayuso C, Sui R, Chen R, Allikmets R, Schorderet DF. Mutations in the Spliceosome Component CWC27 Cause Retinal Degeneration with or without Additional Developmental Anomalies. Am J Hum Genet. 2017 Apr 6;100(4):592-604.

PubMed ID: 
28285769

ZTTK Syndrome

Clinical Characteristics
Ocular Features: 

The eyes are deep-set and the palpebral fissures slant downward.  Optic atrophy is often present.  The majority of individuals have poor visual responses which may also be attributed to central or cortical impairment.  Strabismus and nystagmus are frequently present.

Systemic Features: 

ZTTK syndrome is multisystem malformation and developmental disorder with a heterogeneous clinical presentation.  The facial features might suggest the diagnosis at birth but most of the signs are nonspecific including frontal bossing, underdevelopment of the midface, facial asymmetry, low-set ears, broad and/or depressed nasal bridge, and a short philtrum.  Poor feeding and hypotonia in the neonatal period are usually present and physical growth is subnormal resulting in short stature.

Brain imaging may show abnormal gyral patterns, ventriculomegaly, hypoplasia of the corpus callosum, cerebellar hypoplasia, arachnoid cysts, and loss of periventricular white matter.  About half of patients develop seizures and many have intellectual disabilities.  Spinal anomalies include hemivertebrae with scoliosis and/or kyphosis.  Other skeletal features include joint laxity in some patients and contractures in others.  Arachnodactyly, craniosynostosis, and rib anomalies have been reported.  There may be malformations in the GI, GU, and cardiac systems while immune and coagulation abnormalities have also been reported.

Genetics

Heterozygous mutations in the SON gene (21q22.11) have been identified in patients with this condition.  They may cause truncation of the gene product with haploinsufficiency or, in other patients, a frameshift in the reading.  The SON gene is a master RNA splicing regulator that impacts neurodevelopment.

Virtually all cases are the result of de novo mutations.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No effective treatment has been reported.  Physical therapy and assistive devices may be helpful.

References
Article Title: 

De Novo Truncating Variants in SON Cause Intellectual Disability, Congenital Malformations, and Failure to Thrive

Tokita MJ, Braxton AA, Shao Y, Lewis AM, Vincent M, Kury S, Besnard T, Isidor B, Latypova X, Bezieau S, Liu P, Motter CS, Melver CW, Robin NH, Infante EM, McGuire M, El-Gharbawy A, Littlejohn RO, McLean SD, Bi W, Bacino CA, Lalani SR, Scott DA, Eng CM, Yang Y, Schaaf CP, Walkiewicz MA. De Novo Truncating Variants in SON Cause Intellectual Disability, Congenital Malformations, and Failure to Thrive. Am J Hum Genet. 2016 Sep 1;99(3):720-7.

PubMed ID: 
27545676

De Novo Mutations in SON Disrupt RNA Splicing of Genes Essential for Brain Development and Metabolism, Causing an Intellectual-Disability Syndrome

Kim JH, Shinde DN, Reijnders MR, Hauser NS, Belmonte RL, Wilson GR, Bosch DG, Bubulya PA, Shashi V, Petrovski S, Stone JK, Park EY, Veltman JA, Sinnema M, Stumpel CT, Draaisma JM, Nicolai J; University of Washington Center for Mendelian Genomics, Yntema HG, Lindstrom K, de Vries BB, Jewett T, Santoro SL, Vogt J; Deciphering Developmental Disorders Study, Bachman KK, Seeley AH, Krokosky A, Turner C, Rohena L, Hempel M, Kortum F, Lessel D, Neu A, Strom TM, Wieczorek D, Bramswig N, Laccone FA, Behunova J, Rehder H, Gordon CT, Rio M, Romana S, Tang S, El-Khechen D, Cho MT, McWalter K, Douglas G, Baskin B, Begtrup A, Funari T, Schoch K, Stegmann AP, Stevens SJ, Zhang DE, Traver D, Yao X, MacArthur DG, Brunner HG, Mancini GM, Myers RM, Owen LB, Lim ST, Stachura DL, Vissers LE, Ahn EY. De Novo Mutations in SON Disrupt RNA Splicing of Genes Essential for Brain Development and Metabolism, Causing an Intellectual-Disability Syndrome. Am J Hum Genet. 2016 Sep 1;99(3):711-9.

PubMed ID: 
27545680

Mental Retardation, X-Linked 99, Syndromic, Female-Restricted

Clinical Characteristics
Ocular Features: 

Palpebral fissures are generally shortened and may slant up or down.  Cataracts of unknown morphology have been reported and strabismus is common.

Systemic Features: 

The systemic phenotype is highly variable.  Skull and facial anomalies are common with brachycephaly, bitemporal narrowing, and a broad low nasal bridge. There is general developmental delay in both motor and cognitive abilities.  Patients are short in stature while scoliosis, hip dysplasia, and post-axial polydactyly may be present.  The teeth may be malformed and numerous (29%) of individuals have hypertrichosis.  Nearly a third of individuals have a cleft palate/bifid uvula.   Heart malformations, primarily atrial septal defects, are found in about half of affected individuals and urogenital anomalies such as renal dysplasia are relatively common.  Feeding difficulties have been reported while anal atresia is present in about half of patients.   

Brain imaging reveals hypoplasia of the corpus callosum, enlarged ventricles, Dandy-Walker malformations, cerebellar hypoplasia, and abnormal gyration patterns in the frontal lobe.  Generalized hypotonia has been diagnosed in half of reported patients and seizures occur in 24%.

Genetics

This female-restricted syndrome is caused by heterozygous mutations in the USP9X gene (Xp11.4).  X-chromosome inactivation is skewed greater than 90% in the majority of females but the degree of skewing in one study was independent of clinical severity.  The majority of cases occur de novo.

In males, hemizygous mutations in the USP9X gene (300919) cause a somewhat similar disorder (MRX99) without the majority of the congenital malformations having mainly the intellectual disabilities, hypotonia, and behavioral problems.

Pedigree: 
X-linked dominant, mother affected
Treatment
Treatment Options: 

There is no known treatment for the general disorder but individual anomalies or defects such as atrial septal defects, cleft palate, and anal atresia might be surgically corrected.

References
Article Title: 

De Novo Loss-of-Function Mutations in USP9X Cause a Female-Specific Recognizable Syndrome with Developmental Delay and Congenital Malformations

Reijnders MR, Zachariadis V, Latour B, Jolly L, Mancini GM, Pfundt R, Wu KM, van Ravenswaaij-Arts CM, Veenstra-Knol HE, Anderlid BM, Wood SA, Cheung SW, Barnicoat A, Probst F, Magoulas P, Brooks AS, Malmgren H, Harila-Saari A, Marcelis CM, Vreeburg M, Hobson E, Sutton VR, Stark Z, Vogt J, Cooper N, Lim JY, Price S, Lai AH, Domingo D, Reversade B; DDD Study, Gecz J, Gilissen C, Brunner HG, Kini U, Roepman R, Nordgren A, Kleefstra T. De Novo Loss-of-Function Mutations in USP9X Cause a Female-Specific Recognizable Syndrome with Developmental Delay and Congenital Malformations. Am J Hum Genet. 2016 Feb 4;98(2):373-81.

PubMed ID: 
26833328

Heart and Brain Malformation Syndrome

Clinical Characteristics
Ocular Features: 

Microphthalmia is the cardinal ocular malformation.  Hypertelorism has been described.  Poor vision without further description has also been reported.   

Systemic Features: 

The ears are low-set, malformed, and posteriorly rotated.  The forehead is prominent and there is usually a wide anterior fontanel.  The nasal bridge is wide and frequently depressed while the lower lip is full and may be everted and split.  The palate is highly arched.  Physical growth is slow.  A ventricular septal defect is often present while the valves are hypoplastic and the aortic arch can be interrupted.

Microcephaly is often present and there may a profound delay in psychomotor development with truncal hypotonia and hyperreflexia in the limbs.   Brain imaging shows generalized atrophy with decreased myelination.  Cerebellar vermis hypoplasia has been reported.  Two of 5 patients were reported to have Dandy-Walker malformations, and a thin corpus callosum.  Seizures may occur.

Genetics

Homozygous mutations in the SMG9 gene (19q13.31) are responsible for this condition so far reported in 5 individuals in two unrelated consanguineous Arab families.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Mutations in SMG9, Encoding an Essential Component of Nonsense-Mediated Decay Machinery, Cause a Multiple Congenital Anomaly Syndrome in Humans and Mice

Shaheen R, Anazi S, Ben-Omran T, Seidahmed MZ, Caddle LB, Palmer K, Ali R, Alshidi T, Hagos S, Goodwin L, Hashem M, Wakil SM, Abouelhoda M, Colak D, Murray SA, Alkuraya FS. Mutations in SMG9, Encoding an Essential Component of Nonsense-Mediated Decay Machinery, Cause a Multiple Congenital Anomaly Syndrome in Humans and Mice. Am J Hum Genet. 2016 Apr 7;98(4):643-52.

PubMed ID: 
27018474

Hypotonia, Infantile, with Psychomotor Retardation And Characteristic Facies 1

Clinical Characteristics
Ocular Features: 

Nystagmus, strabismus and sometimes optic atrophy have been noted.  Poor fixation may be present.   

Systemic Features: 

This progressive disorder can be evident at birth based on the facial dysmorphism.  The face appears triangular the forehead is prominent, the nose is small, the ears appear large and low-set.  The mouth appears wide with a thin upper lip.  Early development may be near normal for the first 6 months but thereafter psychomotor regression and slow physical growth are evident.  They have microcephaly and seldom achieve normal milestones.  Spasticity in the extremities and truncal hypotonia with distal muscle atrophy are evident.  The face appears triangular, the forehead is prominent, the nose is small, and the ears appear large and low-set.  Pectus carinatum and pes varus may be present.   Males often have cryptorchidism.

 Brain imaging has revealed cerebellar atrophy and "while matter abnormalities".  Sural nerve biopsies show evidence of infantile neuroaxonal dystrophy.

Some individuals are less severely affected, retain the ability to speak, and are able to walk at least into the second decade of life.

Genetics

Based on transmission patterns this condition is inherited as an autosomal recessive caused by mutations in in the NALCN gene (13q32.3-q33.1.

For somewhat similar disorders caused by mutations in other genes see IHPRF2 (616801) and IHPRF3 (616900).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Corpus Callosum Agenesis with Facial Anomalies and Cerebellar Ataxia

Clinical Characteristics
Ocular Features: 

The thick, bushy eyebrows and long eyelashes are part of the generalized hirsutism.  The eyelids appear puffy.  Strabismus of unknown type has been reported.

Systemic Features: 

Infants are hypertonic at birth but this seems to be less evident as they grow.  Slow physical growth and psychomotor delay are common.  The skull in newborns is small.  The ears are low-set, protruding, and posteriorly rotated.  The nostrils are anteverted and the lower lip protrudes.  There are severe cognitive defects which has been called mental retardation.  Speech is poor or may never develop.  Cerebellar ataxia and uncoordinated hand movements are features.  Brain imaging reveals cerebellar hypoplasia and some degree of corpus callosum agenesis including absence.

Genetics

Homozygous mutations in the FRMD4A gene (10p13) have been found to segregate with this disorder in a large consanguineous Bedouin kindred.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Developmental Delay with Short Stature, Dysmorphic Features, and Sparse Hair

Clinical Characteristics
Ocular Features: 

Patients may have downward-slanting lid fissures, hypertelorism, epicanthal folds, and sparse eyebrows and eyelashes.

Systemic Features: 

Patients have scaphocephaly with or without craniosynostosis and facial dysmorphism with a depressed nasal bridge and micrognathia.  Short stature, sparse hair, and developmental delay are characteristic.  Hypoplastic toenails and dental anomalies are present.  Brain imaging may show Dandy-Walker malformations and cerebellar vermis hypoplasia.  The kidneys may have focal interstitial nephritis and there may be intermittent hematuria and proteinuria in the presence of otherwise normal renal function.  Cardiac septal defects have been noted.

Genetics

Homozygous mutations in the DPH1 gene (17p13.3) are responsible for this disorder.  Two families have been reported with this condition. 

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

Matching two cohorts validates DPH1 as a gene responsible for autosomal recessive intellectual disability with short stature, craniofacial, and ectodermal anomalies

Loucks CM, Parboosingh JS, Shaheen R, Bernier FP, McLeod DR, Seidahmed MZ, Puffenberger EG, Ober C, Hegele RA, Boycott KM, Alkuraya FS, Innes AM. Matching two independent cohorts validates DPH1 as a gene responsible for autosomal recessive intellectual disability with short stature, craniofacial, and ectodermal anomalies. Hum Mutat. 2015 Oct;36(10):1015-9.

PubMed ID: 
26220823

Accelerating novel candidate gene discovery in neurogenetic disorders via whole-exome sequencing of prescreened multiplex consanguineous families

Alazami AM, Patel N, Shamseldin HE, Anazi S, Al-Dosari MS, Alzahrani F, Hijazi H, Alshammari M, Aldahmesh MA, Salih MA, Faqeih E, Alhashem A, Bashiri FA, Al-Owain M, Kentab AY, Sogaty S, Al Tala S, Temsah MH, Tulbah M, Aljelaify RF, Alshahwan SA, Seidahmed MZ, Alhadid AA, Aldhalaan H, AlQallaf F, Kurdi W, Alfadhel M, Babay Z, Alsogheer M, Kaya N, Al-Hassnan ZN, Abdel-Salam GM, Al-Sannaa N, Al Mutairi F, El Khashab HY, Bohlega S, Jia X, Nguyen HC, Hammami R, Adly N, Mohamed JY, Abdulwahab F, Ibrahim N, Naim EA, Al-Younes B, Meyer BF, Hashem M, Shaheen R, Xiong Y, Abouelhoda M, Aldeeri AA, Monies DM, Alkuraya FS. Accelerating novel candidate gene discovery in neurogenetic disorders via whole-exome sequencing of prescreened multiplex consanguineous families. Cell Rep. 2015 Jan 13;10(2):148-61.

PubMed ID: 
25558065

Immunodeficiency-Centromeric Instability-Facial Anomalies Syndrome 3

Clinical Characteristics
Ocular Features: 

Patients have been described as having variable oculofacial features including epicanthal folds, hypertelorism, strabismus, and 'tapetoretinal degeneration'.    

Systemic Features: 

The full phenotype is variable and unknown based on the 5 reported patients from 4 families of whom 3 were consanguineous.  Recurrent infections (especially respiratory and otitis media) seem to be among the most consistent features.  Others include intrauterine growth retardation, developmental delay including psychomotor delays, a flat midface with various anomalies, low-set ears, renal dysgenesis, polydactyly, severe agammaglobulinemia, hypospadias, and cryptorchidism.  Normal T-cell function and normal B cells are present.  Conductive hearing loss, polydactyly, and scoliosis may be features as well.  Two of the 5 reported patients with ICF3 were reported to have mental retardation.  One patient died at the age of 26 years.

Genetics

Homozygosity of CDCA7 (2q31.1) mutations with centromeric instability and hypomethylation of selected juxtacentromeric heterochromatin regions is responsible for this (ICF3) autosomal recessive condition.  There is genetic heterogeneity in ICF (ICF1, ICF2, ICF3, and ICF4 [see 242860).   

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No effective treatment has been reported.

References
Article Title: 

Mutations in CDCA7 and HELLS cause immunodeficiency-centromeric instability-facial anomalies syndrome

Thijssen PE, Ito Y, Grillo G, Wang J, Velasco G, Nitta H, Unoki M, Yoshihara M, Suyama M, Sun Y, Lemmers RJ, de Greef JC, Gennery A, Picco P, Kloeckener-Gruissem B, Gungor T, Reisli I, Picard C, Kebaili K, Roquelaure B, Iwai T, Kondo I, Kubota T, van Ostaijen-Ten Dam MM, van Tol MJ, Weemaes C, Francastel C, van der Maarel SM, Sasaki H. Mutations in CDCA7 and HELLS cause immunodeficiency-centromeric instability-facial anomalies syndrome. Nat Commun. 2015 Jul 28;6:7870.

PubMed ID: 
26216346

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