To the Editor:
1 was pleased to read the article, "Congenital Midline Lesions: Pits and Protuberances," which appeared in the March 1998 issue. While the article presents an excellent review of an oft neglected subject, I feel I must address a "pit" fall.
Dr. Howard's discussion of the management of these lesions was very good; however, there was no mention of the role of the clinical geneticist in the evaluation of these lesions. As Dr. Howard correctly points out, the majority of these lesions are embryologie in origin. It is critical that a clinician experi' enced with developmental anomalies be involved in the care of these patients. As an example, consider the section on branchial cleft cysts and sinuses.
Although branchial cleft abnormalities can occur in isolation (and can be inherited in an autosomal dominant fashion, OMIM #113600),' they also occur in association with other developmental anomalies. One of the most important to recognize is the branchio-oto-renal (BOR) syndrome. First described by Melnick and colleagues in 1975,2 it consists of an association between branchial cysts/fistulae (63%), sensorineural hearing loss (89%), pre-auricular pits (77%), malformed external ears (41%), and renal dysplasia (66%). [Percentages of affected patients as summarized in Recognizable Patterns of Human Mai/orrnan'on.]3 Because the hearing loss and renal dysplasia are not apparent on external clinical examination, a high index of suspicion and a thorough family history are critical to recognize this relatively common (prevalence 1/40,000) syndrome tJhat is responsible for 2% of profound deafness in childhood.
A complete discussion of genetic syndromes associated with midline lesions is clearly beyond the scope of the article or this letter, but I hope your readers will consider a clinical genetics evaluation as part of the work-up of this problem.
Marc S. Williams, MD, FAAP, FACMG
Gunderson-Lutheran Medical Center
La Crosse, Wisconsin
1. Online Mendelian Inheritance in Man. OMIM *". Center for Medical Genetics. Johns Hopkins Universirv (Baltimore. MD) and National Center for Biotechnology Information, National Library of Medicine (Bethesda. MD). 1997.
2. Melnick. M. Bixler. D. Silk. K. Yune. H. Nance. WE Autosomal dominant branchootorenal dysplasia. Bm* Defects. 1975X1(5):121-128.
3. Jones. KL. SmiiA's Recognizable Patterns of Human MaJ/armanon, 5* edn. Philadelphia: W.B. Saunders Companv; 1997.
Dr. Altemeier Responds:
Dr. Williams makes a good point. Actually, it relates back to the time-proven adage that if you find one congenital defect, look for more. And if you find two different malformations, look harder. Marden and colleagues,1 for example, surveyed 4412 newborns over 2 years and found that 13% had had one minor anomaly by surface examination, 0.8% had two, and 0.5% had three or more minor defects. Of those with only one, 3% had one or more major defects by surface examination. Of those with two minor defects, 11% had one or more major anomalies while 90% of those with three or more minor defects had at least one major anomaly.
It should also be routine to take a careful family history whenever you see a defect, and always include, "Has anyone else had anything like this?" Dr. Steve Braddock, the dysmorphologist in genetics here at Missouri University, gave me another pearl. Hearing should be tested in any baby with an ear anomaly. Actually, all babies should have a hearing screen because few problems yield greater benefits from early detection and intervention than hearing loss.
Thanks to Dr. Williams for bringing this to our attention.
1. Maiden PM, Smith DW. McDonald Mj. Congenital anomali in the newborn infant, including minor variations. J Pediatr I964;64:357-371.