renal cysts

Short-Rib Thoracic Dysplasia 9

Clinical Characteristics
Ocular Features: 

A pigmentary retinopathy resembling retinitis pigmentosa is present in the majority of individuals.  Reduced acuity is likely responsible for the associated nystagmus and occasional strabismus.  Night blindness is a feature although the age of onset is unknown.  Visual acuity is decreased in the first decade but at least one patient at age 40 years still had vision of 20/40-20/50.  The ERG shows decreased scotopic and photopic responses as early as 12 years of age.  The retinopathy has been described as an atypical nonpigmented retinal degeneration in the peripheral retina. However, bone-spicule pigmentary deposits have been noted.  The retinal disease is progressive. 

Systemic Features: 

The LFT140 mutation has widespread effects, impacting the kidney, liver and skeletal systems.  The thorax is shortened, while the ribs are abnormally short and may result in respiratory difficulties, recurrent infections, and an early demise.  The middle phalanges of the hands and feet often have cone-shaped epiphyses, especially notable in childhood and leading to brachydactyly.  The long bones are often shortened as well.  The femoral neck can be short while the femoral epiphyses are often flattened.  Microcephaly has been reported in several individuals.

The liver may be enlarged and become fibrotic.  The kidneys often are cystic and histologically may have sclerosing glomerulonephropathy.  Kidney disease has an onset in the first decade and its progression often defines the survival prognosis.  Renal transplantation can be lifesaving when nephronophthisis develops.  Psychomotor delays have been reported but are uncommon. 

Genetics

Homozygous or compound heterozygous mutations in the LFT140 gene (16p13.3) have been identified.  However, there is some genetic heterogeneity since several patients having the typical phenotype have been reported with only heterozygous mutations.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

There is no treatment for the general disease.  Renal and pulmonary function needs to be monitored with intervention as needed.  Some patients have benefitted from renal transplantation.

References
Article Title: 

Combined NGS approaches identify mutations in the intraflagellar transport gene IFT140 in skeletal ciliopathies with early progressive kidney Disease

Schmidts M, Frank V, Eisenberger T, Al Turki S, Bizet AA, Antony D, Rix S, Decker C, Bachmann N, Bald M, Vinke T, Toenshoff B, Di Donato N, Neuhann T, Hartley JL, Maher ER, Bogdanovic R, Peco-Antic A, Mache C, Hurles ME, Joksic I, Guc-Scekic M, Dobricic J, Brankovic-Magic M, Bolz HJ, Pazour GJ, Beales PL, Scambler PJ, Saunier S, Mitchison HM, Bergmann C. Combined NGS approaches identify mutations in the intraflagellar transport gene IFT140 in skeletal ciliopathies with early progressive kidney Disease. Hum Mutat. 2013 May;34(5):714-24.

PubMed ID: 
23418020

Mainzer-Saldino syndrome is a ciliopathy caused by IFT140 mutations

Perrault I, Saunier S, Hanein S, Filhol E, Bizet AA, Collins F, Salih MA, Gerber S, Delphin N, Bigot K, Orssaud C, Silva E, Baudouin V, Oud MM, Shannon N, Le Merrer M, Roche O, Pietrement C, Goumid J, Baumann C, Bole-Feysot C, Nitschke P, Zahrate M, Beales P, Arts HH, Munnich A, Kaplan J, Antignac C, Cormier-Daire V, Rozet JM. Mainzer-Saldino syndrome is a ciliopathy caused by IFT140 mutations. Am J Hum Genet. 2012 May 4;90(5):864-70.

PubMed ID: 
22503633

Meckel Syndrome

Clinical Characteristics
Ocular Features: 

The ocular phenotype is highly variable.  The globe is often malformed or may be clinically absent.  Cryptophthalmos, clinical anophthalmia, and microphthalmos with sclerocornea and microcornea have been reported.  Posterior staphylomas, retinal dysplasia, partial aniridia, cataracts, and hypoplasia or absence of the optic nerve are sometimes seen.  Some patients have incompletely formed eyes with shallow anterior chambers, angle anomalies, and a persistent tunica vasculosa with lens opacification.  Histopathology may reveal thinning of the nerve fiber layer and a paucity of retinal ganglion cells.  The retina has been described as dysplastic with foci of rosette-like structures and abundant glial cells.

Systemic Features: 

Meckel or Meckel-Gruber syndrome is a clinically and genetically heterogeneous group of disorders with severe multisystem manifestations.  The triad of cystic renal disease, polydactyly (and sometimes syndactyly), and a skull malformation (usually an encephalocele) is considered characteristic of MKS.  However, these signs are variable and only about 60% of patients have all three features.  Many patients have additional signs such as malformations of the biliary tree, cleft palate (and/or lip), sloping forehead, low-set ears, short neck, low-set ears, ambiguous genitalia, and short, bowed limb bones.  Pulmonary hypoplasia is common which, together with kidney and liver disease, is responsible for the poor prognosis of most infants. 

Many clinical abnormalities resemble those present in the Smith-Lemli-Opitz syndrome (270400) and in Joubert syndrome (213300).

Genetics

Most conditions in this group are inherited in an autosomal recessive pattern.  Mutations in 9 genes have been identified as responsible for some variant of MKS in which there is a considerable range of clinical expression.  There is significant clinical overlap with Joubert syndrome and it is not surprising that at least 5 of these mutations have been identified in both conditions.  Further nosological confusion is generated by those who consider patients with the severe, lethal phenotype to have Meckel syndrome while those with milder disease are labeled Joubert syndrome, regardless of genotype.

Rare heterozygotes have been reported with isolated features such as polydactyly.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

There is no treatment for this syndrome.  The prognosis for life beyond infancy is poor due to the advanced dysfunction of numerous organs such as the kidney, lungs, liver and the central nervous system.

References
Article Title: 

Clinical and genetic heterogeneity in Meckel syndrome

Paavola P, Salonen R, Baumer A, Schinzel A, Boyd PA, Gould S, Meusburger H, Tenconi R, Barnicoat A, Winter R, Peltonen L. Clinical and genetic heterogeneity in Meckel syndrome. Hum Genet. 1997 Nov;101(1):88-92.

PubMed ID: 
9385376

Von Hippel-Lindau Syndrome

Clinical Characteristics
Ocular Features: 

Retinal angiomas are a feature of this syndrome, occurring in up to 70% of patients and often diagnosed by about age 25 years.  These hemangioblastomas are often connected to prominent arterioles and venules indicative of their vascular nature.  Capillary hamartomas located on or near the optic nerve may mimic papilledema or papillitis.  However, they may also occur throughout the retina and visual morbidity often results from secondary damage due to hemorrhage, exudates, and traction on the retina. When they are bilateral and multicentric the diagnosis of VHL is highly likely.  Patients with VHL tend to develop such tumors at a younger age and have worse visual outcomes than those in patients without VHL.  The impact on vision is responsible for initial presentation in many patients.

Systemic Features: 

Clinical symptoms typically have their onset during the second decade of life.  These commonly (in 35% of patients) result from the presence of a cerebellar hemangioblastoma while overall more than 60% eventually develop this malignancy.  Up to 40% of patients develop renal cell carcinomas and these are a major cause of death.   However, benign and malignant tumors may appear in many organs including the adrenal glands, pancreas, and spinal cord.  Pheochromocytomas occur in 20-35% of individuals and may be bilateral and multifocal.  These can induce an erythrocythemia. Endolymphatic sac tumors occur in about 10% of patients.  Cystic lesions are often associated with the tumors, especially in the pancreas.

Several subtypes have been proposed based on the pattern of malignancies and the types of mutations found in patients.

Genetics

This is an autosomal dominant cancer susceptibility disorder caused by a mutation in the VHL gene located at 3p26-p25.

There is evidence that the phenotype can be modified by variations in the cyclin D1 gene (CCND1) located at 11q13.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Local excision of isolated lesions can be considered in selected cases.  Photocoagulation and cryotherapy of retinal hamartomas can be considered although outcomes are variable depending on location and size of the lesions.

References
Article Title: 

A genetic register for von Hippel-Lindau disease

Maddock IR, Moran A, Maher ER, Teare MD, Norman A, Payne SJ, Whitehouse R, Dodd C, Lavin M, Hartley N, Super M, Evans DG. A genetic register for von Hippel-Lindau disease. J Med Genet. 1996 Feb;33(2):120-7.

PubMed ID: 
8929948

Genetic analysis of von Hippel-Lindau disease

Nordstrom-O'Brien M, van der Luijt RB, van Rooijen E, van den Ouweland AM, Majoor-Krakauer DF, Lolkema MP, van Brussel A, Voest EE, Giles RH. Genetic analysis of von Hippel-Lindau disease. Hum Mutat. 2010 May;31(5):521-37.

PubMed ID: 
20151405

Tuberous Sclerosis 1

Clinical Characteristics
Ocular Features: 

The primary clinical characteristic of tuberous sclerosis of both types 1 and 2 are the occurrence of hamartomas at multiple anatomic sites.  Ocular lesions include those of the eyelids which often appear in early childhood along with other facial angiofibromas (formerly called adenoma sebaceum).  Of greater clinical significance are lesions of the optic nerve and retina reported in about 75% of patients.  The latter (astrocytic hamartomas) may appear as mulberry-like growths typically located in the peripapillary area or as flat translucent lesions located more peripherally.  These are usually static but aggressive growth with retinal detachment and neovascular glaucoma requiring enucleation has been reported in several patients.  Calcification of these lesions may occur in utero or early in life.  These are seldom of clinical significance although optic atrophy has been reported. The iris may have hypopigmented areas.

Systemic Features: 

Hamartomas develop throughout the body in many organs such as the skin, brain, eye, kidney, and heart.  Ninety per cent of patients have skin lesions, including hypomelanotic patches called 'ashleaf' spots that can best be visualized under a Woods lamp.  Symptoms vary widely depending upon the location and size of the growths.  These appear as rhabdomyomas in the heart, angiomyolipomas in the kidneys, bone cysts, and oral fibromas.  Other intracranial growths such as subependymal astrocytomas and cortical tubers are evidence of CNS involvement that can interfere with brain function leading to seizures (in 80% of patients) and subnormal intellectual abilities (60-70% patients) as manifested by learning difficulties, subnormal IQs, as well as social and communication difficulties.   Hypoplasia of dental enamel with pitting in permanent teeth is seen in the majority of patients.  Some progression of tumor size and symptoms may occur.  Most hamartomas are benign but renal carcinoma has been reported in some patients.

Genetics

Many cases (two-thirds) occur sporadically but numerous reported pedigrees are consistent with autosomal dominant inheritance.  Type 1 TSC is caused by mutations in the TSC1 gene (9p34) encoding hamartin and is responsible for the disorder in about 25% of patients.

A more severe phenotype, tuberous sclerosis 2 (613254), is caused by mutations in the TSC2 gene on chromosome 16p13.3 and accounts for the majority of cases of tuberous sclerosis complex.  Genotyping is necessary to determine which mutation is responsible for the TS complex in each case as the phenotypic differences are inadequate to distinguish clinically between types 1 and 2.

New mutations are responsible for 50-70% of cases.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No effective preventative treatment exists but individual lesions can be surgically removed when indicated.

References
Article Title: 

Identification of the tuberous sclerosis gene TSC1 on chromosome 9q34

van Slegtenhorst M, de Hoogt R, Hermans C, Nellist M, Janssen B, Verhoef S, Lindhout D, van den Ouweland A, Halley D, Young J, Burley M, Jeremiah S, Woodward K, Nahmias J, Fox M, Ekong R, Osborne J, Wolfe J, Povey S, Snell RG, Cheadle JP, Jones AC, Tachataki M, Ravine D, Sampson JR, Reeve MP, Richardson P, Wilmer F, Munro C, Hawkins TL, Sepp T, Ali JB, Ward S, Green AJ, Yates JR, Kwiatkowska J, Henske EP, Short MP, Haines JH, Jozwiak S, Kwiatkowski DJ. Identification of the tuberous sclerosis gene TSC1 on chromosome 9q34. Science. 1997 Aug 8;277(5327):805-8.

PubMed ID: 
9242607

Tuberous sclerosis

Curatolo P, Bombardieri R, Jozwiak S. Tuberous sclerosis. Lancet. 2008 Aug 23;372(9639):657-68. Review.

PubMed ID: 
18722871

Alagille Syndrome

Clinical Characteristics
Ocular Features: 

The ocular findings in Alagille syndrome are often of little functional significance but can be sufficient to suggest the diagnosis without further study of the systemic features.  Posterior embryotoxon is found in 95% of individuals while iris abnormalities such as ectopic pupils are seen in 45%, abnormal fundus pigmentation is common (hypopigmentation in 57%, diffuse pigment speckling in 33%), and optic disc anomalies have been reported in 76%.  One study found that 90% of individuals have optic disk drusen by ultrasonography.  The anterior chamber anomalies are considered by some to be characteristic of Axenfeld anomaly.  The presence of these ocular findings in children with cholestasis should suggest Alagille syndrome.  Ocular examination of the parents can also be helpful in this autosomal dominant disorder as some of the same changes are present in one parent in more than a third of cases.

Systemic Features: 

A variety of  systemic features, some of them serious malformations, occur in Alagille syndrome.  Among the most common is a partial intrahepatic biliary atresia leading to cholestasis and jaundice.  Skeletal malformations include 'butterfly' vertebrae, shortened digits, short stature, a broad forehead, and a pointed chin.  The tip of the nose may appear bulbous.  These features have suggested to some that there is a characteristic facial dysmorphology.  Vascular malformations are common including aneurysms affecting major vessels, valvular insufficiency, coarctation of the aorta, and stenosis and these are often responsible for the most serious health problems.  In fact, vascular events have been reported to be responsible for mortality in 34% of one cohort.  Chronic renal insufficiency develops in a minority of patients.  This disorder should always be considered in children with cholestasis, especially when accompanied by cystic kidney disease.  Brain MRIs may show diffuse or focal hyperintensity of white matter even in the absence of hepatic encephalopathy.

Genetics

This is an autosomal dominant condition secondary to various mutations in the JAG1 gene located on chromosome 20 (20p12).  Penetrance is nearly 100% but there is considerable variation in expression.  A far less common variant of this disorder, ALGS2 (610205), is caused by a mutation in the NOTCH2 gene (1p13-p11).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No cure is available but individual organ disease may be treatable.  The ocular abnormalities generally do not cause vision difficulties.

Reversible of white matter changes has been noted in a single child following liver transplantation.

 

References
Article Title: 

CT-defined phenotype of pulmonary artery

Rodriguez RM, Feinstein JA, Chan FP. CT-defined phenotype of pulmonary artery
stenoses in Alagille syndrome
. Pediatr Radiol. 2016 Apr 4. [Epub ahead of print].

PubMed ID: 
27041277

Alagille syndrome: clinical and ocular pathognomonic features

El-Koofy NM, El-Mahdy R, Fahmy ME, El-Hennawy A, Farag MY, El-Karaksy HM. Alagille syndrome: clinical and ocular pathognomonic features. Eur J Ophthalmol. 2010 Jul 28. pii: 192165A5-8631-4C06-9C47-9AD63688B02A. [Epub ahead of print]

PubMed ID: 
20677167

Ocular abnormalities in Alagille syndrome

Hingorani M, Nischal KK, Davies A, Bentley C, Vivian A, Baker AJ, Mieli-Vergani G, Bird AC, Aclimandos WA. Ocular abnormalities in Alagille syndrome. Ophthalmology. 1999 Feb;106(2):330-7.

PubMed ID: 
9951486
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