distichiasis

Blepharocheilodontic Syndrome 2

Clinical Characteristics
Ocular Features: 

The eyelids are disproportionately large with ectropion of the lower lid.  There is often a duplicate row of lashes (distichiasis) and there may be lagophthalmos and euryblepharon present.  Hypertelorism has been described. 

Systemic Features: 

The teeth are often conical and some may be absent.  Cleft lip and palate are often present.  The forehead is prominent and the frontal hairline is posteriorly located.

Genetics

Heterozygous mutations in the CTNND1 gene (11q12.1) are responsible for this condition.

Blepharocheilodontic syndrome 1 results from heterozygous mutations in the CDH1 gene (16q22.1).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Treatment consists of surgical repair of dental, eyelid, and oral defects.

References
Article Title: 

Blepharocheilodontic Syndrome 1

Clinical Characteristics
Ocular Features: 

The eyelids are disproportionately large with an associated lagophthalmos and lower lid ectropion.  The upper eyelids may have a double row of lashes (distichiasis).  Hypertelorism and a broad nasal root have been reported.

Systemic Features: 

A cleft lip and palate are major features and are usually bilateral.  The teeth are conically shaped with microdontia and oligodontia (involving both primary and secondary dentition) often present as well.  Several newborns have had an imperforate anus. Scalp hair may be sparse and hypoplastic nails have been described.  Hypothyroidism and thyroid agenesis has been documented in several patients.

Genetics

This is an autosomal dominant condition resulting from mutations in the CDH1 gene (16q22.1).

Blepharocheilodontic syndrome 2 is caused by mutations in the CTNND1 gene (16q22.1).

Other conditions with distichiasis include Blatt distichiasis (126300) and lymphedema-distichiasis (153400).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Treatment consists of correction of individual anomalies such as eyelid, oral, and dental malformations.

References
Article Title: 

Blepharo-cheilo-dontic (BCD) syndrome

Gorlin RJ, Zellweger H, Curtis MW, Wiedemann HR, Warburg M, Majewski F, Gillessen-Kaesbach G, Prahl-Andersen B, Zackai E. Blepharo-cheilo-dontic (BCD) syndrome. Am J Med Genet. 1996 Oct 16;65(2):109-12.

PubMed ID: 
8911600

Setleis Syndrome

Clinical Characteristics
Ocular Features: 

The eyebrows slant upward and the lashes may be absent or appear in double rows as in distichiasis.  The periorbital skin can appear 'puckered with puffiness'.  The palpebral fissures appear short in some individuals.

Systemic Features: 

This condition is associated with a variety of facial skin anomalies.  The overall facial appearance has been described as 'leonine".  The facial skin often has some redundancy with a rubbery feel and may appear 'puffy' or wrinkled and puckered about the eyes. The lips are large.  The overall appearance has been described as 'leonine'. The nasal ridge can be flat and the nose can have a bulbous tip.  The teeth may be conical in shape.

Genetics

The genetic basis for this disorder seems to lie in heterozygous mutations in the TWIST2 gene (2q37.3).  Parent to child transmission has also been reported for some features but the signs in parents may be subtle.. 

The TWIST2 mutation was not present in several unrelated probands suggesting there is some genetic heterogeneity. Further, Brauer syndrome (136500) (focal facial dermal dysplasia or FFDD type I) is clinically somewhat similar to Setleis syndrome with respect to the distribution and nature of facial skin lesions and it has been suggested that the two disorders may be one and the same.  The gene responsible for Brauer syndrome has not been found but the condition is inherited in autosomal dominant fashion.  It is possible therefore that families labeled Setleis with an AD pattern of transmission actually have Brauer syndrome.  It should also be noted that the ablepharon-macrostonia syndrome (200110) and Barber-Say syndrome (209885) are also caused by mutations in TWIST2 and have some features in common with Setleis syndrome.

 

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Recurrent Mutations in the Basic Domain of TWIST2 Cause Ablepharon Macrostomia and Barber-Say Syndromes

Marchegiani S, Davis T, Tessadori F, van Haaften G, Brancati F, Hoischen A, Huang H, Valkanas E, Pusey B, Schanze D, Venselaar H, Vulto-van Silfhout AT, Wolfe LA, Tifft CJ, Zerfas PM, Zambruno G, Kariminejad A, Sabbagh-Kermani F, Lee J, Tsokos MG, Lee CC, Ferraz V, da Silva EM, Stevens CA, Roche N, Bartsch O, Farndon P, Bermejo-Sanchez E, Brooks BP, Maduro V, Dallapiccola B, Ramos FJ, Chung HY, Le Caignec C, Martins F, Jacyk WK, Mazzanti L, Brunner HG, Bakkers J, Lin S, Malicdan MC, Boerkoel CF, Gahl WA, de Vries BB, van Haelst MM, Zenker M, Markello TC. Recurrent Mutations in the Basic Domain of TWIST2 Cause Ablepharon Macrostomia and Barber-Say Syndromes. Am J Hum Genet. 2015 Jul 2;97(1):99-110.

PubMed ID: 
26119818

Lymphedema-Distichiasis Syndrome

Clinical Characteristics
Ocular Features: 

This form of lymphedema is associated with distichiasis, often with trichiasis and significant corneal damage in about 75% of patients.  Onset of symptoms may occur at any age but usually during childhood or adolescence.  Photophobia, epiphora, corneal erosions, ptosis, and partial ectropion of the lids may also be seen.  The secondary symptoms of trichiasis are not always present and slit lamp examination of the lashes may be necessary to see the duplicated row of lashes.  The lashes often grow out of the Meibomian orifices.

Systemic Features: 

Cardiac defects, cleft palate, and spinal extradural cysts occur in some families.  Type II diabetes and interstitial nephritis have been reported.  The lymph channels in the lower extremities may be normal or increased in number, especially below the knee where pitting edema is most often first seen, even as early as the first decade of life.  Lymphedema occurs earlier in males and secondary cellulitis is a greater risk. It is usually confined to the lower extremities and is often asymmetrical.  Not all patients have the complete syndrome, while lymphedema and distichiasis can be inherited as individual disorders without being associated.  Males are more likely to have the complete syndrome.

Several families with this syndrome secondary to mutations in the FOXC2 have been reported to have renal anomalies ranging from kidney agenesis to malrotation. 

Genetics

This disorder is inherited in an autosomal dominant pattern and several families have been found to have mutations in the FOXC2 gene on chromosome 16 (16q24.3).  A Chinese family with an affected father and two affected offspring (one male and one female) has been reported with distichiasis but no lymphedema.  A premature stop codon was found in the FOXC2 transcription gene (16q24.1) in these family members suggesting that they may have had the lymphedema-distichiasis syndrome instead.

Blatt distichiasis is a unique disorder without the lymphedema (126300). 

Double rows of eyelashes are also part of the blepharocheilodontic syndrome (119580).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Electrolysis of individual misdirected lashes can be applied.  Prompt treatment of lid cellulitis is important.

References
Article Title: 

Renal anomalies and lymphedema distichiasis syndrome

Jones GE, Richmond AK, Navti O, Mousa HA, Abbs S, Thompson E, Mansour S, Vasudevan PC. Renal anomalies and lymphedema distichiasis syndrome. A rare association? Am J Med Genet A. 2017 May;173(8):2251-2256.

PubMed ID: 
28544699

Hereditary lymphedema and distichiasis

Kolin T, Johns KJ, Wadlington WB, Butler MG, Sunalp MA, Wright KW. Hereditary lymphedema and distichiasis. Arch Ophthalmol. 1991 Jul;109(7):980-1.

PubMed ID: 
2064580

Blatt Distichiasis

Clinical Characteristics
Ocular Features: 

Distichiasis, or two rows of eyelashes, is sometimes confused with districhiasis (three rows of lashes) or trichiasis.  True distichiasis often occurs in all four lids and is sometimes associated with other lid anomalies such as ptosis, trichiasis, corneal damage, congenital ectropion and absence of Meibomian glands.  It has occasionally been found only in the lower lids and much more rarely just in the upper lids. In distichiasis, the second row of lashes emerges from the orifices of the Meibomian glands which distinguishes it from acquired trichiasis in which the normally placed lashes are misdirected.  The abnormal lashes are usually thinner, shorter, and less pigmented than the normal lashes.  They number from 3-20 with an average of 12-15.

Systemic Features: 

No consistent systemic associations have been reported.

Genetics

Pedigrees consistent with autosomal dominant inheritance have been reported but no locus or gene has been identified. 

A Chinese family with affected father and one affected male and female offspring has been reported with distichiasis but no lymphedema.  A premature stop codon was found in the FOXC2 transcription gene (16q24.1) in these family members suggesting that they may have had the lymphedema-distichiasis syndrome (153400) instead. 

In some patients with anhidrotic ectodermal dysplasia (224900) there is also a double row of lashes but these exit anterior to the Meibomian gland orifices.

Distichiasis also occurs as part of the lymphedema-distichiasis syndrome (153400) as well as the blepharocheilodontic syndrome (119580). Aberrant rows of eyelashes have been reported in Setleis syndrome (227260).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Electrolysis of misdirected lashes may be used when individual lashes cause corneal damage.

References
Article Title: 

Distichiasis

Fox SA. Distichiasis. Am J Ophthalmol. 1962 Jan;53:14-8.

PubMed ID: 
13894397
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