Familial natal teeth across three generations – the genetic implication

INTRODUCTION

The presence of teeth in newborns is uncommon, varying from 1:6000 to 1:800 cases, occurring in general with incidences of two or three teeth, and their etiology remains unclear, with proposed causes including genetic predisposition, endocrine factors, and superficial positioning of the dental lamina.¹ Natal teeth are teeth present at birth, and they hold a lot of misconceptions and cultural taboos. They are further accompanied by various difficulties, such as pain on suckling and refusal to feed, faced by the mother and the child due to the natal teeth.

Familial cases suggest an autosomal dominant inheritance pattern.² This case emphasizes the importance of detailed family history in assessing neonates with natal teeth.

Literature review

Inheritance seems to play a role in the causation of this anomaly and it has been considered to be a major factor by many authors described a family in which the eldest son had one natal tooth and the third son three.³ The children of this latter son had teeth erupting in their second month. Coleman reported an infant with natal teeth whose sister and father were also born with two lower incisors erupted.⁴ Asana in India reported natal teeth in two children of the same father by different wives. Of the 12 cases in Sheffield, 3 gave a definite family history of natal or neonatal teeth and 4 of the 7 cases reported from the Leeds University Child Health Department gave a definite family history of this Gardiner.⁵ This degree of association as a familial characteristic is well above chance. Gates stated that "the condition (i.e., natal teeth) is probably an irregular dominant, but the irregularity might be due to the presence of an inhibitor or to two genes being acquired".⁶ Holt et al reported a family in which natal teeth occurred in members of three successive generations.⁷ Kates et al reported an instance in which twins were born with two lower central incisors each. Their father also had had teeth present at birth. Balard reported a case in which twins were born with teeth.⁹ Rosenhaupt described a family in which the oldest son was born with a tooth erupted and the third son with three teeth erupted.¹⁰ The children of the third son had teeth erupted during the second month. Asana reported the ease of two infants with natal teeth born of the same father but by different mothers.¹¹ Herpin reported the case of two infants in one family with neonatal teeth.¹² It may be concluded from a perusal of the literature that natal and neonatal teeth may occur in families and might at times be on an inherited basis. It is to be regretted that most of the ease reports lacked specific information in this direction. Ten of the twenty-four infants whose case reports were analyzed (41.6 per cent) had other siblings or parents showing the same anomaly.¹³

CASE REPORT

A full-term male neonate, born via normal vaginal delivery, was noted to have two fully erupted lower central incisors at birth (Figure 1). The teeth were firmly attached, non-mobile. No feeding difficulties or Riga-Fede ulcers were noted. Systemic examination was unremarkable, with no dysmorphic features or congenital anomalies.

The parents reported multiple family members across three generations had natal teeth at birth (Figure 2). Maternal great-grandmother (reported to have 2 natal incisors teeth), maternal grandmother (reported to have 2 natal incisors teeth) and the baby’s mother (also was reported to have 2 natal incisor teeth). None of the family members required dental extraction or had history of aspiration.

No imaging was done as teeth were firmly attached and non-mobile. Parents were reassured about the benign nature of natal teeth and advised monitoring for mobility and complications (aspiration risk, Riga-Fede disease) and follow-up planned for eruption sequence monitoring and dental evaluation at 6 months.

DISCUSSION

A hereditary factor has been identified in several studies on natal and neonatal teeth. Massler and Savara reported a positive family history in 10 of 24 cases, while Gardiner identified hereditary influence in 7 of 19 cases.^4,5 Halls (1957) documented a family involving three brothers, one of whom presented with two incisors at birth, while another developed a tooth eruption nine days postnatally. In contrast, Allwright described 26 cases of natal or neonatal teeth among Chinese infants in Hong Kong and identified a hereditary component in only one case, suggesting possible ethnic or population-based variability in genetic influence.^13-15

The strong familial clustering observed across multiple reports supports a genetic basis for natal teeth. In the present family, pedigree analysis suggests an X-linked dominant pattern of inheritance with incomplete penetrance. The condition is observed exclusively in females across multiple generations, with no affected males, supporting an X-linked mode of inheritance. Affected females transmit the trait to their daughters in a manner consistent with dominant inheritance. However, not all female offspring are affected, indicating variable penetrance, possibly due to skewed X-chromosome inactivation, genetic modifiers, or environmental influences.^8,16

Future studies evaluating X-inactivation patterns, gene expression profiles, and epigenetic factors in affected individuals may provide further insight into the observed variability in phenotypic expression.

This case highlights the familial nature of natal teeth and emphasizes the importance of obtaining a detailed family history during neonatal oral examinations. Further molecular genetic studies are required to confirm inheritance patterns and identify underlying genetic mechanisms.

CONCLUSION

Natal teeth are rare developmental anomalies that may occur sporadically or have a familial predisposition. This case demonstrates a striking familial occurrence across three generations, suggesting a possible hereditary basis with an X-linked dominant pattern and incomplete penetrance. Although the absence of affected males and transmission through affected females supports this pattern, molecular genetic studies are required for confirmation. A detailed family history should therefore be an integral part of the evaluation of neonates presenting with natal teeth, both to identify familial cases and to facilitate appropriate counselling and follow-up. In asymptomatic, stable teeth, conservative management with regular monitoring is appropriate, with dental intervention reserved for mobility, feeding difficulties, traumatic ulceration, or aspiration risk.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

REFERENCES

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