- Wolf-Hirschhorn Syndrome.

Wolf-Hirschhorn Syndrome

*Pathophysiology:-
results from deletion of the distal short arm of chromosome no 4 (1).

* Clinically, the minimal diagnostic criteria for Wolf-Hirschhorn syndrome (ie, ‘‘core’’ phenotype) consists of typical facial appearance , mental retardation, growth delay, hypotonia and seizures (or EEG anomalies)(2).

* Different categories of the Wolf-Hirschhorn syndrome phenotype are defined according to the extent of the chromosome.4 deletion(2):-

• 1st category :- caused by small deletion that is usually associated with a mild phenotype, lacking major malformations. This category is likely under-diagnosed.
• 2nd category :- caused by large deletions that cause the widely recognizable Wolf-Hirschhorn syndrome phenotype.
• 3rd category :- caused by very large deletions that cause a severe phenotype that can hardly be defined as typical Wolf-Hirschhorn syndrome.

* Factors affecting prognosis include (2):-

• extent of the deletion.
• occurrence of complex chromosome anomalies.
• severity of seizures.

*Karyotype (1):-
46,xx,4p-(female).
46,xy,4p-(male).
(4p- means that the short arm of chromosome 4 is shorter than normal).

* Clinical picture(3),(4):-

• Growth retardation.
• CNS:- Developmental delay and mental retardation of varying degree,microcephaly, seizures, congenital hypotonia with muscle hypotrophy particularly of the lower limbs.
• Skull:- Frontal bossing, high frontal hairline, hemangioma over forehead or glabella, scalp defect with or without underlying bony defect.
• Face:- Characteristic features including prominent glabella, hypertelorism, broad beaked nose, and frontal bossing, collectively described as "Greek warrior helmet" facies.
• Eyes:- Hypertelorism, down-slanting palpebral fissures, epicanthal folds, strabismus, coloboma, proptosis.
• Nose :- Broad or beaked nose, nasolacrimal duct stenosis or atresia
• Mouth:- Short upper lip, short philtrum, cleft lip or palate, bifid uvula, carplike mouth, micrognathia, retrognathia
• Teeth:- Hypodontia
• Ears:- Low-set ears; large, floppy, or misshapen ears; microtia; preauricular dimples; chronic otitis media with effusion; sensorineural hearing loss.
• Cardiovascular:- Atrial septal defect, ventricular septal defect.
• Pulmonary:- lung hypoplasia secondary to diaphragmatic hernia.
• GIT:- Diastasis recti, umbilical or inguinal hernias, accessory spleens, absent gallbladder, diaphragmatic hernia, intestinal malrotation.
• Genitourinary:- Hypoplastic kidneys, cystic dysplastic kidneys, unilateral renal agenesis, hydronephrosis, exstrophy of bladder, hypoplastic external genitalia.
• Skeletal:- Long slender fingers with additional flexion creases, long narrow chest, hypoplastic widely spaced nipples, hypoplasia or duplication of thumbs and great toes, hypoplasia of pubic bones.

Return to list of Paediatric medical syndromes here

*References:-
(1) Principles of histology vol1,staff members ,faculty of medicine,mansoura university,ch3,p.g74.
(2) Zollino M, Murdolo M, Marangi G, et al. On the nosology and pathogenesis of
Wolf-Hirschhorn syndrome: genotype-phenotype correlation analysis of 80 patients
and literature review. Am J Med Genet C Semin Med Genet. Nov 15 2008;148C(4):257-69.[Medline].
(3)Battaglia A, Carey JC, Wright TJ. Wolf-Hirschhorn (4p-) syndrome. Adv Pediatr. 2001;48:75-113. [Medline].(4)South ST, Whitby H, Battaglia A, Carey JC, Brothman AR. Comprehensive analysis of Wolf-Hirschhorn syndrome using array CGH indicates a high prevalence of translocations. Eur J Hum Genet. Jan 2008;16(1):45-52. [Medline]. [Full Text].