What is 4Q Deletion Syndrome
Chromosome 4q Deletion Syndrome is a rare chromosomal disorder in which there is deletion of a portion of the 4th chromosome. Deletions may be in the middle of the chromosome arm (“interstitial”) or at the end “terminal”) and have varying effects. There are enough common features for children with deletions anywhere along the range that it has been called a syndrome, but as with most rare genetic issues, the differences between children can be tremendous. Visually there are commonalities between kids, much as with Down Syndrome, in this case, the most distinctive visual features include short limbs, a high “frontal bossing” on the forehead, large head, wide set eyes, low set ears, thin upper lip and short, high nose. This gives children a “babyish” look for longer, which can be compounded by motor issues.
Also known as
· Chromosome 4, 4q Terminal Deletion Syndrome
· 4q Deletion Syndrome, Partial
· Del(4q) Syndrome, Partial
· Distal 4q- Syndrome
· Distal 4q Monosomy
· Chromosome 4, Partial Monosomy 4q
There are many symptoms and characteristics that affect people with Chromosome 4q Deletion Syndrome.
· Abnormalities of the hands and feet- Hands and feet may be shorter and wider than normal, “tiny feet” are very common. Toes may bend at funny places (the second joint bending down for example) or overlap and turned in pinky fingers
· Dystonic or “funny” feet (they bend in a strange place or have overlapping toes or are particularly flat or rocker-bottom)
· Short limbs compared to torso size are also not unusual, short wide hands with turned in pinkies and feet are also common
· Flat bridge of nose
· Gastrointestinal reflux
· Growth deficiency after birth – Reflux and coordination issues may make sucking and eating difficult, and even fully nourished children may not grow very well on a normal diet
· Hearing issues
· Hypotonia and ataxia – Low muscle tone and poor muscle control due to an error in signaling between the brain and the muscle can contribute to global delays
· Large head
· Low muscle tone is very common
· Low set rotated ears
· Malformations of the skull and facial region – Large head, craniostenosis, wide set eyes, small facial features, distinctive nose (wide, flat, high bridge), thin lips, small or receding chin
· Slight epicanthic folds
· Structural heart defects – Heart defects appear to be very dependent on the specific genes involved in the deletion. For example, most children with (del)4q21.1-21.3 do not have heart issues
· Neurological problems such as seizures, hypotonia, and delayed motor development (i.e. sitting up, walking, etc)[/list]
Treatments
Most treatments are symptomatic, but it is important that all children with 4q deletion syndrome have testing done for metabolic abnormalities.
Avoid citrus foods – Some children also show symptoms of problems with citric acid, it is suspected that this may be due to problems with the Kreb’s Cycle. Restricted citric acid diets have been helpful for some children. Some common foods which include citrates are: Most infant formulas
It is inadvisable to restrict diet without evidence of a problem, but if your child is having issues with diaper rash that won’t respond to treatment, do consider citrates as a culprit. This may also explain problems post-surgery, as most surgeries involve use of oral medications that contain citrates for flavor
Many children (even those without a frank deficiency) will benefit from use of Coenzyme Q10 (doses range from 20 mg/kg to 5 mg/kg depending on response and type of supplementation.) CoQ10 seems to help both reflux and growth issues in some children
Oral medications (multivitamins, topical ibuprofen is one alternative, tylenol suppositories are another for pain meds. Watch carefully for inhaled medications, there may be idiosyncratic reactions to epinephrine due to the citrates use to buffer it)
Other treatments that have been helpful include Carnitine (For a child with a test result showing very low carnitine) and R-Lipoic-Acid (for any child with “metabolic symptoms” such as low tone)
Some children with 4q deletions show signs of reflux, treatment of that may help growth issues
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