Handbook of Genetic Counseling/Cleft Lip - Isolated, Unilateral, Incomplete
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Cleft Lip - Isolated, Unilateral, Incomplete
- Acknowledge previous contact
- What were you hoping to gain from today's session?
- What concerns and questions do you have?
- Outline session agenda
- Interim history
- Dr. will examine to rule out possible syndromes associated with CL
- We aren't expecting Dr. to find anything that makes him suspicious.
- Have you found out anything new about the family history?
- Any new births, deaths, or diagnoses?
Cleft lip and palate
- Before genetic counseling can be given, numerous syndromes must be excluded.
- Definition: CL/CP due to a failure of the union of the frontonasal process of the face with the lateral maxillary prominence at about 3-4 weeks post conception (35 days gestation)
- Classification of clefts
- Nonsyndromic vs. syndromic
- 80% are unilateral, 20% bilateral, extends to the palate in 70% of unilateral cases and 85% of bilateral cases
- Incomplete or complete (involving the lip and the anterior maxilla vs. involving the lip, anterior maxilla, hard and soft palate)
- Unilateral clefting commonly occurs on the left (2x more frequently than right)
- Male to female ratio is 2:1
- CL +/- CP occurs in 1:1000 Caucasian births, 1.7:1000 Asian births and 1:2500 AA
- Isolated cleft lip and palate account for 25% of the cases of clefting
- Left unilateral clefts, right unilateral clefts, and bilateral clefts occur at a 6:3:1 ratio.
Inheritance and Recurrence Risks
- Most isolated occurrences are inherited multifactorially
- Background risk: 0.1% (Harper)
- RR- 3-7%, empiric
- 2-4% risk for offspring of an affected parent
- 2nd degree relative: 0.6% risk (Harper)
- Specific factors increase the risk for CL/CP
- Severity of the trait (unilateral vs. bilateral; complete vs. incomplete)
- Number of affected relatives
- Sex affected (whether the person is of the sex opposite the most often affected)
- How closely the individual is related to the affected person)
Multifactorial Inheritance and Genetic counseling
- A condition that is caused by several genes and the environment
- Threshold model- baby inherits genes from both parents that increase the risk for cl/cp, then in combination with certain environmental factors the risk goes beyond the threshold level and the baby develops a cleft
- Although there are multiple genes involved 3 predisposing genes have been identified.
- Explaining this to parents:
- Children with cl/cp inherit genes in a random way from their parents
- Parents cannot control which genes they pass on
- Some of these genes contribute to facial development. We know that there are over 100 genes that contribute to the development of the lip and palate; there have been 3 genes found that we call predisposing genes- which means that in animal models we have been able to show that disruption or changes in this gene can lead to clefting.
- when the lip forms in early development, cells migrate together to close the lip
- Multiple genes tell those cells to move the way that they are supposed to
- It takes more than genetic factors for someone to develop a cleft
- Environmental factors play a big role.
- We know some of the factors that interact with genes to cause clefts (smoking, alcohol, some medications) but we don't know them all.
- There are some protective factors- folic acid
- Timing is important, the lip is completely closed by the 35th day of gestational development (medicine or other factors after this time wouldn't have an effect on the lip)
- Explaining this to parents:
- Reassurance: you did everything within your control to have a healthy baby. Even if risk factors were present (smoking, drinking etc.) the mother should be reassured that even without these factors the baby could have been born with a cleft.
- Currently there is no way to guarantee that a baby isn't born with a cleft. The best thing to do in future pregnancies is to avoid smoking, drinking, and certain medications (anticonvulsants, retinoic acid), and to take folic acid periconceptionally.
- Feeding issues? Make sure the baby is getting enough nutrition. Infants with isolated cleft lip (without cleft palate) seldom have problems feeding by breast or bottle.
- Surgery: objective- to close the lip to create a pleasing face that will develop normally with minimal scarring.
- Closure is performed when the baby is approximately 3 months old at weighs at least 10 pounds.
- Correction of the nasal deformity is usually performed at the time of the lip repair.
- Additional surgeries will be necessary to enhance the appearance of the lip and/or nose.
- Initial surgery lasts ~2-3 hours and the hospital stay is usually 2-4 days.
- During this time special considerations are necessary for feeding and positioning. Elbows are restrained from bending. Positioning the child in an infant seat prevents rolling over and injuring the lip/nose. No pacifiers or nipples allowed. Fed with a special syringe feeder with a soft tube. It takes about 3 weeks for the wound to heal enough to stop these special precautions.
- The lip scar is initially red and swollen, but begins to mature and improve in appearance in ~6 months.
- Isolated cleft lip- no expected problems with hearing or speech.
- Possible problems with teeth…there can be missing or crooked teeth in the area of the cleft.
- Pediatrician for routine care
- Contact craniofacial team- referral made, scheduled for the Nov. infant/toddler meeting- letter has been sent.
- help with feeding, special bottles, positioning of the baby
- The craniofacial team has a psychologist that can help with the emotional concerns of having a child with a facial cleft. Interested in scheduling an appointment?
- Follow up with Dr. Billmier
- and Dental services?
- Practical Genetic Counseling
- Emery and Rimoin
- Bender PL. Genetics of Cleft Lip and Palate. (2000). Journal of Pediatric Nursing. 15:4.
- Clefts of the Lip and Palate. 1997. Tennessee Craniofacial Center.
The information in this outline was last updated in 2002.