microphthalmia

Bosma Arhinia Microphthalmia Syndrome

Clinical Characteristics
Ocular Features: 

Microphthalmia or clinical anophthalmia are usually present.  Iris colobomas are frequent features.  Occluded or absent nasolacrimal ducts have been reported.

Systemic Features: 

Arhina with anosmia is the most striking feature but it is usually accompanied by midface hypoplasia, a highly arched (or cleft) palate, and preauricular pits.  The nasal bones along with the cribriform plate, and other septal structures may be missing.  Maxillary and paranasal sinuses, together with the olfactory bulbs are often absent.  Intelligence is usually normal.

Choanal atresia is often present.  Hypogonadotropic hypogonadism with micropenis and cryptorchidism is an important feature in males.  Females may experience pubertal delay with menarche anomalies.  

Genetics

Heterozygous mutations in the SMCHD1 gene (18p11) are responsible for this disorder.  There is considerable clinical heterogeneity with many carriers having only minor manifestations.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment for the general disorder has been described.

References
Article Title: 

De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development

Gordon CT, Xue S, Yigit G, Filali H, Chen K, Rosin N, Yoshiura KI, Oufadem M, Beck TJ, McGowan R, Magee AC, Altmuller J, Dion C, Thiele H, Gurzau AD, Nurnberg P, Meschede D, Muhlbauer W, Okamoto N, Varghese V, Irving R, Sigaudy S, Williams D, Ahmed SF, Bonnard C, Kong MK, Ratbi I, Fejjal N, Fikri M, Elalaoui SC, Reigstad H, Bole-Feysot C, Nitschke P, Ragge N, Levy N, Tuncbilek G, Teo AS, Cunningham ML, Sefiani A, Kayserili H, Murphy JM, Chatdokmaiprai C, Hillmer AM, Wattanasirichaigoon D, Lyonnet S, Magdinier F, Javed A, Blewitt ME, Amiel J, Wollnik B, Reversade B. De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development. Nat Genet. 2017 Feb;49(2):249-255.

PubMed ID: 
28067911

Coloboma, Microphthalmia, Albinism, and Deafness

Clinical Characteristics
Ocular Features: 

A 5 year old male has been described with uveal colobomas in microphthalmic eyes plus small corneas with a pannus, dense cataracts, translucent irides, and hypopigmentation of the skin, hair and eyes.  A brain MRI showed hypoplasia of the optic nerves and chiasm.   

A 9 month old female from another family had severe microphthalmia and small optic nerves.  The internal ocular features were not reported.

Systemic Features: 

The complete phenotype is uncertain since it is based on only two reported and unrelated individuals.  The head circumference one one patient was consistent with macrocephaly accompanied by frontal bossing, shallow orbits, preauricular pits and posteriorly rotated ears.  A skeletal survey revealed evidence for osteopetrosis.  He had a sensorineural hearing deficit said to be congenital in onset.

The other patient, a 9 month old female, belonged to another nonconsanguineous family, and had similar skeletal and craniofacial features with the addition of micrognathia and hypotonia.  Congenital neurosensory hearing loss and general lack of pigmentation were noted.

All four parents have congenital sensorineural hearing loss, blue irides and fair skin with premature graying of hair.  Four sibs in the two families have phenotypes similar to that of the parents.  Only one child, a female, had no features of the phenotype.

Genetics

This condition, so far reported only in a male and a female in unrelated families, is the result of doubly heterozygous mutations in the MITF gene (3p13).  One mutation that causes Waardenburg syndrome 2  (WS2A) (193510) is combined with a dominant-negative allele (c.952_954delAGA [p.Arg318del]) to produce the phenotype.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

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

Gracile Bone Dysplasia

Clinical Characteristics
Ocular Features: 

The eyes have been described as small.  Aniridia may be present.

Systemic Features: 

This is a usually fatal form of skeletal dysplasia with splenic and ocular features as well.  In utero death is not uncommon while newborns may not survive the neonatal period.  The face has been described as dysmorphic with a high forehead, flat nasal bridge, a cloverleaf-shaped skull, and hypoplastic cranial bones with premature suture closure.  The long bones are dysplastic as well with thinned diaphyses (sometimes fractured in utero), growth plate disorganization, excessive remodeling, and signs of arrested growth.  The ribs share in the dysplasia but pulmonary hypoplasia has also been described.  Most individuals have short limbs.

The spleen can be hypoplastic or aplastic and ascites has been noted in several infants.  Failure to thrive is common and seizures have been reported.  Males may have micropenis and hypospadias while females have been described with labial fusion.  

Low parathyroid hormone levels and hypocalcemia has been reported in most individuals.

Genetics

Heterozygous mutations in the FAM111A gene (11q12.1) have been associated with this disorder.  The functional role of FAM111A products is unknown but likely play a role in calcium metabolism, parathyroid hormone secretion, and osseous development.

Mutations in the same gene can be responsible for the allelic autosomal dominant Kenny-Caffey syndrome (127000) with some similar features.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

FAM111A mutations result in hypoparathyroidism and impaired skeletal development

Unger S, Gorna MW, Le Bechec A, Do Vale-Pereira S, Bedeschi MF, Geiberger S, Grigelioniene G, Horemuzova E, Lalatta F, Lausch E, Magnani C, Nampoothiri S, Nishimura G, Petrella D, Rojas-Ringeling F, Utsunomiya A, Zabel B, Pradervand S, Harshman K, Campos-Xavier B, Bonafe L, Superti-Furga G, Stevenson B, Superti-Furga A. FAM111A mutations result in hypoparathyroidism and impaired skeletal development. Am J Hum Genet. 2013 Jun 6;92(6):990-5.

PubMed ID: 
23684011

Kenny-Caffey Syndrome, Type 2

Clinical Characteristics
Ocular Features: 

Congenital cataracts have been reported in one patient.  There is a report of pseudopapilledema in a 6 year old and another patient has been described with tortuous and dilated retinal vessels.  The hyperopia is likely the result of the small globes.  In an autopsied patient microscopic calcification was noted in the cornea and the retina.

Systemic Features: 

Hypocalcemia and hyperphosphatemia similar to hypoparathyroidism is seen in individuals with KCS2 but it may be transient and self-limited.  Macrocephaly with short stature is characteristic.  Alopecia, delayed closure of the anterior fontanel, and apparent thickening of the cortex in long bones may be seen.  Males have small testicles but there is no evidence regarding fertility.  In an autopsied case no parathyroid tissue could be identified.  Brain imaging may show calcification in the basal ganglia, dentate nuclei, and parts of the cerebrum and cerebellum.  Intelligence is normal.

Genetics

Several heterozygous mutations in the FAM111A gene (11q12.1) have been found.  Many of these seem to be new mutations but there are a number of published families in which there was transmission from mother to child (of both sexes).

Heterozygous mutations in the same gene are responsible for the autosomal dominant  allelic disorder known as Gracile Bone Dysplasia (602361). 

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Normalization of serum calcium and phosphorous levels would likely be beneficial but complete correction of all the findings is unlikely.  Removal of congenital cataracts should be considered.

References
Article Title: 

FAM111A mutations result in hypoparathyroidism and impaired skeletal development

Unger S, Gorna MW, Le Bechec A, Do Vale-Pereira S, Bedeschi MF, Geiberger S, Grigelioniene G, Horemuzova E, Lalatta F, Lausch E, Magnani C, Nampoothiri S, Nishimura G, Petrella D, Rojas-Ringeling F, Utsunomiya A, Zabel B, Pradervand S, Harshman K, Campos-Xavier B, Bonafe L, Superti-Furga G, Stevenson B, Superti-Furga A. FAM111A mutations result in hypoparathyroidism and impaired skeletal development. Am J Hum Genet. 2013 Jun 6;92(6):990-5.

PubMed ID: 
23684011

Ocular findings in Kenny's syndrome

Boynton JR, Pheasant TR, Johnson BL, Levin DB, Streeten BW. Ocular findings in Kenny's syndrome. Arch Ophthalmol. 1979 May;97(5):896-900.

PubMed ID: 
444124

Kabuki Syndrome 1

Clinical Characteristics
Ocular Features: 

The facial features and specifically the periocular anomalies are diagnostic and responsible for the eponymic designation (resembling the make-up of actors of a Japanese theatrical form known as Kabuki). The lid fissures are long and narrow and the lateral third of the lower lids are often everted.  The eyebrows are highly-arched and broad with some sparsity especially in the lateral portion.  The eyelashes are thick and ptosis is often noted. Strabismus may be present.  Blue sclerae have been reported.

Some patients may have extreme microphthalmia.

Systemic Features: 

Post-natal growth delay and short stature are present as a result of anomalies in the vertebrae often with secondary scoliosis.  Persistence of the fetal fingertip pads is common. Hypotonia and joint hypermobility have been noted and some degree of intellectual disability is common.  Seizures have been reported but these are not common. Cleft lip and palate are seen in about a third of patients and the palate is highly arched in about 75%.  The teeth are small, frequently malformed and widely spaced.  Feeding difficulties are common.  Anal anomalies such as imperforate anus, anovestibular fistulas, and an anteriorly placed opening may be present, especially in females.  A small penis, hypospadias, and cryptorchidism are common in males.

An ill-defined immune deficit seems to be a common feature as evident by susceptibility to infections, primarily otitis media in infants and later recurrent sinopulmonary infections.   The majority of patients have hypogammaglobulinemia with a variable pattern of antibody abnormalities resembling common variable immune deficiency and especially low levels of serum IgA.  

Hearing loss is seen in nearly half of patients, some of which is no doubt due to recurrent otitis media but CT radiography has demonstrated dysplastic morphology of inner ear structures and the petrous bone.  The ears are large and cupped and preauricular pits may be present as well.

Biliary atresia and a variety of morphological anomalies of the kidney have been reported.  Renal failure can occur.  Perhaps as many as 58% of patients have congenital heart defects, mostly septal in location. 

Genetics

Heterozygous mutations in KMT2D (12q13.12) (also called MLL2) are responsible for Kabuki syndrome 1 but parental transmission to offspring is rare and the majority of patients occur sporadically.  There is also an X-linked form (Kabuki 2) caused by mutations in KDM5A (Xp11.3).  Insufficient clinical data regarding the X-linked phenotype so far has precluded the ability to distinguish the two disorders without genotyping.

Residual genetic heterogeneity remains, however, as a substantial proportion of patients do not have mutations in the two mutant genes known.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

There is no general treatment for this condition.  Management guidelines are available (Management of Kabuki Syndrome).

References
Article Title: 

MLL2 and KDM6A mutations in patients with Kabuki syndrome

Miyake N, Koshimizu E, Okamoto N, Mizuno S, Ogata T, Nagai T, Kosho T, Ohashi H, Kato M, Sasaki G, Mabe H, Watanabe Y, Yoshino M, Matsuishi T, Takanashi J, Shotelersuk V, Tekin M, Ochi N, Kubota M, Ito N, Ihara K, Hara T, Tonoki H, Ohta T, Saito K, Matsuo M, Urano M, Enokizono T, Sato A, Tanaka H, Ogawa A, Fujita T, Hiraki Y, Kitanaka S, Matsubara Y, Makita T, Taguri M, Nakashima M, Tsurusaki Y, Saitsu H, Yoshiura K, Matsumoto N, Niikawa N. MLL2 and KDM6A mutations in patients with Kabuki syndrome. Am J Med Genet A. 2013 Sep;161A(9):2234-43. 

PubMed ID: 
23913813

Chorioretinopathy with Microcephaly 2

Clinical Characteristics
Ocular Features: 

Microphthalmia and microcornea are seen in most individuals and one patient had unilateral clinical anophthalmia. Hyperopia and cataracts may be present. Nystagmus is common.  One patient had a corneal opacity.  The chorioretinopathy has not been described beyond evidence of the maculopathy, attenuated retinal vessels, and occasionally hyperpigmented zones.  The ERG is either not recordable or consistent with a severe rod-cone dystrophy.  Vitreous inclusions and a 'vitreoretinal dystrophy' with falciform retinal folds were noted in several patients.  A traction detachment was present in one and bilateral serous detachments were noted in another.

Systemic Features: 

Patients have mild to severe microcephaly (up to -15 SD) with psychomotor delays.  Profound intellectual disability is a consistent feature.  Physical growth is retarded and patients have shortness of stature.  Most patients are unable to sit, stand, or walk unassisted.  One patient died at 5.5 years of age while another was alive at 20 years of age.  Rare patients may have hearing loss and seizures.

Scoliosis, kyphosis, and lordosis may be seen while  other skeletal malformations seem to occur sporadically e.g., triphalangeal thumbs, brachydactyly, postaxial polydactyly, and restricted large joint motion.  

The forehead slopes markedly.  Neuroimaging shows a consistent reduction in cortex size with simple gyral folding while the cerebellum and the brain stem are also small.  Subarachnoid cysts have been noted in several patients and the corpus callosum may be short or otherwise malformed.

Genetics

Homozygous mutations in the PLK4 gene (4q28.2) segregate with this condition.  Its product localizes to centrioles and plays a central role in centriole duplication.

For a somewhat similar condition but without the sloping forhead see Chorioretinoapathy with Microcephaly 1 (251270) but resulting from homozygous mutations in TUBGCP6.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is know.

References
Article Title: 

Mutations in PLK4, encoding a master regulator of centriole biogenesis, cause microcephaly, growth failure and retinopathy

Martin CA, Ahmad I, Klingseisen A, Hussain MS, Bicknell LS, Leitch A, Nurnberg G, Toliat MR, Murray JE, Hunt D, Khan F, Ali Z, Tinschert S, Ding J, Keith C, Harley ME, Heyn P, Muller R, Hoffmann I, Daire VC, Dollfus H, Dupuis L, Bashamboo A, McElreavey K, Kariminejad A, Mendoza-Londono R, Moore AT, Saggar A, Schlechter C, Weleber R, Thiele H, Altmuller J, Hohne W, Hurles ME, Noegel AA, Baig SM, Nurnberg P, Jackson AP. Mutations in PLK4, encoding a master regulator of centriole biogenesis, cause microcephaly, growth failure and retinopathy. Nat Genet. 2014 Dec;46(12):1283-92.

PubMed ID: 
25344692

Galloway-Mowat Syndrome

Clinical Characteristics
Ocular Features: 

Microphthalmia, hypertelorism, epicanthal folds and ptosis are prominent ocular features.  Other manifestations include corneal opacities, cataracts, and optic atrophy.  Nystagmus of a roving nature is seen in all individuals and is usually present at birth.  There is evidence of visual impairment in more than 90% of individuals.  Features of an anterior chamber dysgenesis such as a hypoplastic iris are sometimes present.

The ocular features of this syndrome have not been fully described.

Systemic Features: 

Infants are born with low birth weight due to intrauterine growth retardation and there is often a history of oligohydramnios.  Newborns are often floppy and hypotonic although spasticity may develop later.  A small midface and microcephaly (80%) with a sloping forehead and a flat occiput are frequently evident.  The ears are large, floppy, and low-set while the hard palate is highly arched and the degree of micrognathia can be severe.  The fists are often clenched and the digits can appear narrow and arachnodactylous.  Hiatal hernias may be present.

Many patients develop features of the nephrotic syndrome in the first year of life with proteinuria and hypoalbuminemia due to glomerular kidney disease and renal system malformations.  Renal biopsies show focal segmental glomerulosclerosis in the majority of glomeruli.

Evidence of abnormal neuronal migration with brain deformities such as cystic changes, porencephaly, encephalomalacia, and spinal canal anomalies have been reported.  MRI imaging shows diffuse cortical and cerebellar atrophy atrophic optic nerves, and thinning of the corpus callosum.  The normal striated layers of the lateral geniculate nuclei are obliterated.  The cerebellum shows severe cellular disorganization with profound depletion of granule cells and excessive Bergmann gliosis.  The vermis is shortened. 

Multifocal seizures are sometimes (40%) seen in infancy and early childhood and the EEG generally shows slowed and disorganized backgound and sometimes a high-voltage hypsarrhythmia.  The degree of psychomotor delay and intellectual disability is often severe.   Most patients are unable to sit independently (90%), ambulate (90%), or make purposeful hand movements (77%).  The majority (87%) of children have extrapyramidal movements and a combination of axial dystonia and limb chorea.  Mean age of death is about 11 years (2.7 to 28 years in one series) and most die from renal failure.

Genetics

Gallaway-Mowat syndrome is likely a spectrum of disease.  Homozygous mutations in the WDR73 gene (15q25) are responsible for one form of this syndrome.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

There is no treatment for GAMOS.

References
Article Title: 

Recessive nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum is caused by homozygous protein-truncating mutations of WDR73

Jinks RN, Puffenberger EG, Baple E, Harding B, Crino P, Fogo AB, Wenger O, Xin B, Koehler AE, McGlincy MH, Provencher MM, Smith JD, Tran L, Al Turki S, Chioza BA, Cross H, Harlalka GV, Hurles ME, Maroofian R, Heaps AD, Morton MC, Stempak L, Hildebrandt F, Sadowski CE, Zaritsky J, Campellone K, Morton DH, Wang H, Crosby A, Strauss KA. Recessive nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum is caused by homozygous protein-truncating mutations of WDR73. Brain. 2015 Aug;138(Pt 8):2173-90.  PubMed PMID: 26070982.

PubMed ID: 
26070982

Loss-of-Function Mutations in WDR73 Are Responsible for Microcephaly and Steroid-Resistant Nephrotic Syndrome: Galloway-Mowat Syndrome

Colin E, Huynh Cong E, Mollet G, Guichet A, Gribouval O, Arrondel C, Boyer O, Daniel L, Gubler MC, Ekinci Z, Tsimaratos M, Chabrol B, Boddaert N, Verloes A, Chevrollier A, Gueguen N, Desquiret-Dumas V, Ferre M, Procaccio V, Richard L, Funalot B, Moncla A, Bonneau D, Antignac C. Loss-of-Function Mutations in WDR73 Are Responsible for Microcephaly and Steroid-Resistant Nephrotic Syndrome: Galloway-Mowat Syndrome. Am J Hum Genet. 2014 Dec 4;95(6):637-48..

PubMed ID: 
25466283

Familial Exudative Vitreoretinopathy, EVR5

Clinical Characteristics
Ocular Features: 

The clinical picture is highly heterogeneous.  Abnormal peripheral vascularization of the retina is generally evident and most individuals have retinal exudates.  The amount of exudation is dependent to some extent upon age.  Fluorescein angiography may demonstrate incomplete vascularization of the peripheral retina.  The ocular phenotype can resemble retinal dysplasia.  Occasional infants can have severe retinal disease and may be considered blind but many individuals have minimal disease and retain good vision into adulthood.  Unfortunately, traction retinal detachments may develop at any time and are responsible for blindness in some patients. 

Cataracts are sometimes present. Ectopic pupils, lack of well-defined pupillary collarettes, remnants of the fetal vascular stalk, and shallowing of the anterior chamber have been noted in several patients.  Microphthalmia and corneal opacities may also be present.  Horizontal nystagmus can be seen in severely affected babies before one month of age.

Systemic Features: 

No systemic features have been reported.

Genetics

This disorder can be inherited in an autosomal dominant pattern as the result of heterozygous mutations in the TSPAN12 gene (7q31.31).  However, individuals with more severe disease may have homozygous mutations in this gene. 

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

This disorder can be inherited in an autosomal dominant pattern as the result of heterozygous mutations in the TSPAN12 gene (7q31.31).  However, individuals with more severe disease may have homozygous or compound heterozygous mutations in this gene. 

References
Article Title: 

Microphthalmia, Syndromic 10

Clinical Characteristics
Ocular Features: 

Microphthalmia seems to be a common feature.  The globes have anterior-posterior dimensions of 5-8 mm.  No internal ocular structures can be visualized and individuals are likely blind.  The corneal diameters in two patients were measured at 3-4 mm.  The optic nerves have been described as ‘slender’ on brain imaging.

Systemic Features: 

Head circumference ranges from the 10th to the 25th percentile at birth  Psychomotor development has been described as normal during the first 6 to 8 months but is followed by rapid deterioration in performance with spasticity, vomiting and continuous crying.  An MRI on one 3 day old patient was reported as normal while at 15 months of age there was atrophy of the vermis and corpus callosum and at 8 years of age the atrophy of these structures was even more extensive.  Similar atrophy patterns were seen in the two other patients and eventually all cerebral while matter is lost and there is atrophy of the brainstem as well. 

Genetics

Three children from 3 consanguineous Pakistani families have been reported but no locus or mutation has been identified.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

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