Feingold Syndrome Type 2
A rare, genetic congenital malformation syndrome characterized by microcephaly, short stature, digital anomalies (brachymesophalangy, fifth finger clinodactyly, syndactyly of toes and hypoplastic thumbs) and mild intellectual disabilities but that lacks the manifestations of gastrointestinal atresia.
Epidemiology
Feingold syndrome type 2 (FS2) is extremely rare with less than 20 patients described in the literature to date.
Clinical description
FS2 patients present with microcephaly, brachydactyly, brachymesophalangy of the second and fifth fingers, hypoplastic thumbs and toe syndactyly as seen in FS1. Mild intellectual disability is also noted. Unlike FS1, patients with FS2 lack any form of gastrointestinal atresia and they do not display short palpebral fissures.
Etiology
FS2 is thought to be caused by a hemizygous deletion in the MIR17HG gene on chromosome 13q31.3. This is the first example of a syndromic development deficit in humans that is caused by a miRNA gene.
Diagnostic methods
Diagnosis is suspected on clinical presentation and can be confirmed by high-resolution CGH (comparative genomic hybridization) arrays.
Differential diagnosis
Differential diagnosis of FS2 includes FS type 1 (FS1), VACTERL association, CHARGE syndrome, brachydactyly type A4 and Fanconi anemia.
Antenatal diagnosis
Prenatal testing is possible in FS2 families with a known MIR17HG mutation or deletion.
Genetic counseling
FS2 is inherited in an autosomal dominant manner; however, most cases arise de novo. Genetic counseling is possible.
Management and treatment
Extensive medical examinations are needed to identify possible anomalies of the heart or kidneys. Management of FS2 typically centers for long-term medical sequelae. Occupational therapy / surgical intervention for finger/toe anomalies may be required. Renal and cardiac anomalies should receive the standard treatments and prophylactic antibiotics may be beneficial. Special education is recommended for children and adults with learning deficits. Hearing loss should equally be monitored by an audiologist. Cochlear implants are possible in certain cases.
Prognosis
Prognosis depends on congenital malformations (especially cardiac and renal anomalies) present. If optimal surgical correction is achievable, the prognosis can be relatively positive, though some patients will continue to be affected by their congenital malformations throughout life.