In vivo imaging of the cornea in a patient with lecithin-cholesterol acyltransferase deficiency

Corneal thickness in the case of familial lecithin-cholesterol acyltransferase deficiency

Purpose

We report our findings of a patient with a definitive diagnosis of familial lecithin-cholesterol acyltransferase deficiency (FLD), whose corneal thickness was measured using swept-source optical coherence tomography (OCT) and who underwent an ophthalmologic therapeutic intervention.

Observations

The patient was a 78-year-old Japanese man diagnosed with FLD at the age of 52 years. This was his first ever visit to an ophthalmology clinic. Slit lamp microscopy revealed bilateral diffuse corneal opacities and cataracts, angioid streaks of the retina, and macular atrophy in the fundus. The central corneal thickness, measured with swept-source OCT, was within the normal range in both eyes. Deep lamellar keratoplasty, phacoemulsification, and intraocular lens insertion were performed simultaneously for the left eye. The right eye was treated only using deep lamellar keratoplasty.

Conclusions and importance

As seen in patients with fish-eye disease, the central corneal thickness in this patient with FLD was within the normal range. Since FLD is a rare disease, it is essential to collect and examine further data on corneal thickness.

LCAT deficiency: a systematic review with the clinical and genetic description of Mexican kindred

BACKGROUND

LCAT (lecithin-cholesterol acyltransferase) deficiency is characterized by two distinct phenotypes, familial LCAT deficiency (FLD) and Fish Eye disease (FED). This is the first systematic review evaluating the ethnic distribution of LCAT deficiency, with particular emphasis on Latin America and the discussion of three Mexican-Mestizo probands.

METHODS

A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analysis) Statement in Pubmed and SciELO. Articles which described subjects with LCAT deficiency syndromes and an assessment of the ethnic group to which the subject pertained, were included.

RESULTS

The systematic review revealed 215 cases (154 FLD, 41 FED and 20 unclassified) pertaining to 33 ethnic/racial groups. There was no association between genetic alteration and ethnicity. The mean age of diagnosis was 42 ± 16.5 years, with fish eye disease identified later than familial LCAT deficiency (55 ± 13.8 vs. 41 ± 14.7 years respectively). The prevalence of premature coronary heart disease was significantly greater in FED vs. FLD. In Latin America, 48 cases of LCAT deficiency have been published from six countries (Argentina (1 unclassified), Brazil (38 FLD), Chile (1 FLD), Columbia (1 FLD), Ecuador (1 FLD) and Mexico (4 FLD, 1 FED and 1 unclassified). Of the Mexican probands, one showed a novel LCAT mutation.

CONCLUSIONS

The systematic review shows that LCAT deficiency syndromes are clinically and genetically heterogeneous. No association was confirmed between ethnicity and LCAT mutation. There was a significantly greater risk of premature coronary artery disease in fish eye disease compared to familial LCAT deficiency. In FLD, the emphasis should be in preventing both cardiovascular disease and the progression of renal disease, while in FED, cardiovascular risk management should be the priority. The LCAT mutations discussed in this article are the only ones reported in the Mexican- Amerindian population.

Ocular and Genetic Characteristics Observed in Two Cases of Fish-Eye Disease

PURPOSE

To present ocular findings and anterior segment-optical coherence tomography (AS-OCT) imaging findings of 2 cases of fish-eye disease (FED) involving 2 novel genetic variants of the lecithin-cholesterol acyltransferase (LCAT) gene.

METHODS

A case report.

RESULTS

A 46-year-old woman and 63-year-old man presented with blurred vision, burning sensation, and whitening of both eyes for 2 and 3 years, respectively. Ophthalmologic examination revealed slightly decreased visual acuity, yellowish-white diffuse corneal opacities causing corneal clouding, and dry eye disease bilaterally in both patients. AS-OCT imaging demonstrated diffuse hyperreflective corneal opacities predominantly located in the anterior stroma. On systemic examination, both patients had very low plasma high-density lipoprotein cholesterol levels. However, they did not have any systemic associations with familial LCAT deficiency or Tangier disease, which are differential diagnoses for corneal clouding and low plasma high-density lipoprotein cholesterol. Both patients were diagnosed with FED based on clinical findings. Furthermore, genetic analysis, in which novel variants of c.86A>G (p.Asn29Ser) in the first exon and c.1052A>G (p.Tyr351Cys) in the sixth exon on the LCAT gene were detected, confirmed the diagnosis.

CONCLUSIONS

Although it is a rare genetic disorder, FED should be considered in the differential diagnosis of corneal clouding. Corneal lipid deposits, visible on AS-OCT are suggestive of FED, and genetic analysis can be used to confirm the clinical diagnosis. Finally, there may be a relationship between dry eye disease and LCAT enzyme deficiency disorders, which should be investigated in further studies.

Clinical features and visual function in a patient with Fish-eye disease: Quantitative measurements and optical coherence tomography

Purpose

We describe a case of fish-eye disease (FED) where the clinical features and visual function were investigated using anterior segment optical coherence tomography (OCT) and quantitative measurements.

Observations

A 36-year-old Japanese woman with FED presented with bilateral corneal opacities and visual complaints. Both contrast sensitivity and straylight were measured and OCT imaging was performed. Contrast sensitivity and straylight measurements revealed remarkably decreased visual function, despite good visual acuity. OCT demonstrated homogenously hyper-reflective corneal opacification, and a normal total corneal thickness.

Conclusions and Importance

The findings from this case suggest that OCT is useful for analyzing the clinical features of FED, and that the quantitative measurement of visual function furthers the understanding of vision-related symptoms in FED, despite good visual acuity.

Novel Missense LCAT Gene Mutation Associated with an Atypical Phenotype of Familial LCAT Deficiency in Two Portuguese Brothers

Familial lecithin-cholesterol acyltransferase deficiency (FLD) is a rare recessive disorder of cholesterol metabolism, caused by loss-of-function mutations in the human LCAT gene, leading to alterations in the lipid/lipoprotein profile, with extremely low HDL levels.The classical FLD phenotype is characterized by diffuse corneal opacification, haemolytic anaemia and proteinuric chronic kidney disease (CKD); an incomplete form, only affecting the corneas, has been reported in a few families worldwide.We describe an intermediate phenotype of LCAT deficiency, with CKD preceding the development of corneal clouding, in two Portuguese brothers apparently homozygous for a novel missense LCAT gene mutation. The atypical phenotype, the diagnosis of membranous nephropathy in the proband's native kidney biopsy, the late-onset and delayed recognition of the corneal opacification, the co-segregation with Gilbert syndrome and the late recurrence of the primary disease in kidney allograft all contributed to obscure the diagnosis of an LCAT deficiency syndrome for many years.A major teaching point is that on standard light microscopy examination the kidney biopsies of patients with LCAT deficiency with residual enzyme activity may not show significant vacuolization and may be misdiagnosed as membranous nephropathy. The cases of these two patients also illustrate the importance of performing detailed physical examination in young adults presenting with proteinuric CKD, as the most important clue to the diagnosis of FLD is in the eyes.

A novel homozygous mutation causing lecithin-cholesterol acyltransferase deficiency in a proband of Romanian origin with a record of extreme gestational hyperlipidemia

A patient from Romania with extraordinarily high total cholesterol levels and clinical and biochemical features consistent with familial lecithin-cholesterol acyltransferase deficiency is reported. The genetic analysis performed on our proband showed a novel homozygous mutation on codon 119 of lecithin-cholesterol acyltransferase gene that causes the substitution of glycine by aspartate. The same mutation, also in homozygosis, was observed in her older sister, whereas his brother presented it in heterozygosis.

Familial lecithin:cholesterol acyltransferase deficiency: First-in-human treatment with enzyme replacement

BACKGROUND

Humans with familial lecithin:cholesterol acyltransferase (LCAT) deficiency (FLD) have extremely low or undetectable high-density lipoprotein cholesterol (HDL-C) levels and by early adulthood develop many manifestations of the disorder, including corneal opacities, anemia, and renal disease.

OBJECTIVE

To determine if infusions of recombinant human LCAT (rhLCAT) could reverse the anemia, halt progression of renal disease, and normalize HDL in FLD.

METHODS

rhLCAT (ACP-501) was infused intravenously over 1 hour on 3 occasions in a dose optimization phase (0.3, 3.0, and 9.0 mg/kg), then 3.0 or 9.0 mg/kg every 1 to 2 weeks for 7 months in a maintenance phase. Plasma lipoproteins, lipids, LCAT levels, and several measures of renal function and other clinical labs were monitored.

RESULTS

LCAT concentration peaked at the end of each infusion and decreased to near baseline over 7 days. Renal function generally stabilized or improved and the anemia improved. After infusion, HDL-C rapidly increased, peaking near normal in 8 to 12 hours; analysis of HDL particles by various methods all revealed rapid sequential disappearance of preβ-HDL and small α-4 HDL and appearance of normal α-HDL. Low-density lipoprotein cholesterol increased more slowly than HDL-C. Of note, triglyceride routinely decreased after meals after infusion, in contrast to the usual postprandial increase in the absence of rhLCAT infusion.

CONCLUSIONS

rhLCAT infusions were well tolerated in this first-in-human study in FLD; the anemia improved, as did most parameters related to renal function in spite of advanced disease. Plasma lipids transiently normalized, and there was rapid sequential conversion of small preβ-HDL particles to mature spherical α-HDL particles.

Homozygous lecithin:cholesterol acyltransferase (LCAT) deficiency due to a new loss of function mutation and review of the literature

BACKGROUND

A case of homozygous familial lecithin:cholesterol acyltransferase (LCAT) deficiency with a novel homozygous LCAT missense mutation (replacement of methionine by arginine at position 293 in the amino acid sequence of the LCAT protein) is reported.

METHODS AND RESULTS

The probable diagnosis was suggested by findings of marked high density lipoprotein (HDL) deficiency, corneal opacification, anemia, and renal insufficiency. The diagnosis was confirmed by two dimensional gel electrophoresis of HDL, the measurement of free and esterified cholesterol, and sequencing of the LCAT gene.

CONCLUSIONS

In our view the most important aspects of therapy to prevent the kidney disease that these patients develop is careful control of blood pressure and lifestyle measures to optimize non HDL lipoproteins. In the future replacement therapy by gene transfer or other methods may become available.

Marked HDL deficiency and premature coronary heart disease

PURPOSE OF REVIEW

Our purpose is to review recent publications in the area of marked human HDL deficiency, HDL particles, coronary heart disease (CHD), amyloidosis, the immune response, and kidney disease.

RECENT FINDINGS

Lack of detectable plasma apolipoprotein (apo) A-I can be due to DNA deletions, rearrangements, or nonsense or frameshift mutations within the APOA1 gene resulting in a lack of apoA-I secretion. Such patients have marked HDL deficiency, normal levels of triglycerides and LDL cholesterol, and can have xanthomas and premature CHD. ApoA-I variants with amino acid substitutions, especially in the region of amino acid residues 50-93 and 170-178, have been associated with amyloidosis. Patients with homozygous Tangier disease have defective cellular cholesterol efflux due to mutations in the adenosine triphosphate-binding cassette transporter A1, detectable plasma apoA-I levels and prebeta-1 HDL in their plasma. They have decreased LDL cholesterol levels and can develop neuropathy and premature CHD. Patients with lecithin: cholesterol acyltransferase deficiency have both prebeta-1 and alpha-4 HDL present in their plasma and develop corneal opacities, anemia, proteinuria, and kidney failure.

SUMMARY

Patients with marked HDL deficiency can have great differences in their clinical phenotype depending on the underlying defect.