dilated cardiomyopathy

Vici Syndrome

Clinical Characteristics
Ocular Features: 

Congenital cataracts, both unilateral and bilateral are common.  The fundus appears hypopigmented. Nystagmus, optic neuropathy, and mild ptosis have been reported.  Nothing is known regarding acuity. 

Systemic Features: 

Infants at birth have striking hypotonia with a weak cry and feeding difficulties.  Dysmorphic features such as micrognathia, microcephaly, low-set ears, some degree of generalized hypopigmentation (hair and skin), and a broad nose with a long philtrum may be present. The face may appear triangular.  Cleft lip and palate may be present.  Evidence of cardiac dysfunction may also be present early with both dilated and hypertrophic cardiomyopathy reported.  Hearing loss has been reported in some individuals.  Recurrent infections are common and immunologic studies have revealed, in some patients, granulocytopenia, low T cell counts (primarily T4+ cells), thymic dysplasia, and low levels of IgG.  Seizures may occur.  Liver dysfunction has been variably reported.

Neurological and brain evaluations have reported agenesis of the corpus callosum, defects in the septum pellucidum, and hypoplasia of the cerebellar vermis along with pontocerebellar hypoplasia.  Psychomotor retardation is severe in most individuals along with general growth retardation.

Histologic studies of skeletal muscle fibers have shown considerable variation in fiber size, centralized nuclei, fucsinophilic inclusions, and enlarged abnormal mitochondria.  Other central nervous system abnormalities include in some individuals a paucity of white matter, schizencephaly, neuronal heterotopias, and enlargement of the ventricles.

The cumulative effects of these multiorgan abnormalities lead to death within the first year or two of life, generally of heart failure or sepsis. 

Genetics

Homozygous or compound heterozygous mutations in the EPG5 gene (18q12.3) have been associated with this condition.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Vici syndrome: a

Byrne S, Dionisi-Vici C, Smith L, Gautel M, Jungbluth H. Vici syndrome: a
review. Orphanet J Rare Dis. 2016 Feb 29;11(1):

PubMed ID: 
4772338

Recessive mutations in EPG5 cause Vici syndrome, a multisystem disorder with defective autophagy

Cullup T, Kho AL, Dionisi-Vici C, Brandmeier B, Smith F, Urry Z, Simpson MA, Yau S, Bertini E, McClelland V, Al-Owain M, Koelker S, Koerner C, Hoffmann GF, Wijburg FA, ten Hoedt AE, Rogers RC, Manchester D, Miyata R, Hayashi M, Said E, Soler D, Kroisel PM, Windpassinger C, Filloux FM, Al-Kaabi S, Hertecant J, Del Campo M, Buk S, Bodi I, Goebel HH, Sewry CA, Abbs S, Mohammed S, Josifova D, Gautel M, Jungbluth H. Recessive mutations in EPG5 cause Vici syndrome, a multisystem disorder with defective autophagy. Nat Genet. 2013 Jan;45(1):83-7.

PubMed ID: 
23222957

Alström Syndrome

Clinical Characteristics
Ocular Features: 

Progressive failure of rods and cones begins in the first year of life and inevitably leads to blindness.  Central vision is lost first and nystagmus in early childhood results.   Photophobia can be evident in the first year of life.  Early ERGs show severe impairment of cone responses with little or no rod dysfunction.  In the second and third decades all rod and cone responses are extinguished.  Vision can be less than 20/400 by the age of 10 years and usually all light perception is lost by the beginning of the third decade.  Pale optic nerves with retinal arteriorlar narrowing and posterior subcapsular cataracts have been seen.

Systemic Features: 

This is a multisystem disease with onset in the first year of life.  Infants may have a normal birth weight but develop truncal obesity in the first year.  Hearing loss is evident in the first decade.  Insulin resistant type 2 diabetes mellitus with hyperinsulinemia often occurs in childhood and may be accompanied by hypothyroidism and hypogonadotropic hypogonadism.  Acanthosis nigricans and some degree of pulmonary dysfunction are common.  The majority of individuals (70%) develop restrictive or dilated cardiomyopathy, many in the first months of life, resulting in cardiac failure.  The liver may become cirrhotic and renal failure occurs late.  Intelligence is usually normal but many patients (25-30%) have early delays in their developmental milestones perhaps secondary to growth hormone deficiency which has been reported (98% are short in stature).  Lifespan is short and many die in childhood.  Few live beyond the age of 40 years.

Alstrom syndrome has some similarities to Bardet-Biedl syndrome (209900) but differs in the absence of mental deficiency and polydactyly.

Genetics

This is an autosomal recessive disorder resulting from homozygous mutations in the ALMS1 gene on chromosome 2 (2p13).  The ALMS1 protein product is found in many cells throughout the body and is located in centrosomes and the base of cilia.  Its function is unknown.

More than 320 mutations have been reported. However, many cases remain in which no mutation has been found suggesting additional genetic heterogeneity remains.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is available for the basic disease.

References
Article Title: 

Alström Syndrome: Mutation Spectrum of ALMS1

Marshall JD, Muller J, Collin GB, Milan G, Kingsmore SF, Dinwiddie D, Farrow EG, Miller NA, Favaretto F, Maffei P, Dollfus H, Vettor R, Naggert JK. Alstrom Syndrome: Mutation Spectrum of ALMS1. Hum Mutat. 2015 Apr 2. doi: 10.1002/humu.22796. [Epub ahead of print].

PubMed ID: 
25846608

Alström syndrome

Marshall JD, Beck S, Maffei P, Naggert JK. Alstrom syndrome. Eur J Hum Genet. 2007 Dec;15(12):1193-202.

PubMed ID: 
17940554
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